Logo PTB
symbolic picture: "magazines"

Archive of PTB News

PTB-News 3.2019PTB-News 3.2019

Trial of a dental drilling guide produced by additive manufacturing for the drilling of holes to fit dental implants into artificial jaw models with only few abutment teeth. The drilling angle α and the drilling depth were measured by means of computed tomography

Medicine is placing high expectations on implants and auxiliary materials that are manufactured specifically for each individual patient. This can be done by means of additive manufacturing (3D printing), which allows nearly any complex shape to be produced. Before starting to use such implants widely, the medical sector and certification bodies demand proof of the fact that their high quality is...

[ more ]
Schematic setup of virtual mammography

Within the scope of the mammography screening program, approved devices must ensure that radiologists are able to reliably detect even small contrasts. The imaging quality of each device is therefore checked every year by means of monitoring measurements. For this purpose, test images of phantoms are taken and assessed by means of procedures of data analysis. PTB has developed a simulation...

[ more ]
The OBCA mounted next to the transfer standard on the translation system at PTB's Reduced Background Calibration Facility 2. (Photo credit: Fraunhofer IOF, CYMER)

At PTB, the reference radiation source of the EnMAP satellite for the remote sensing of the Earth has been calibrated with high resolution. This ensures the long-term comparability and traceability of its global measurement data from the fields of geobiology, geochemistry and geophysics.

[ more ]
PTB's caesium fountain clocks CSF2 (in the foreground) and CSF1. The atoms are cooled by lasers in the lower part of the vacuum setup and then launched upwards. In the upper part of the setup, they are irradiated with microwaves during their flight.

PTB's two caesium fountain clocks, CSF1 and CSF2, have been established as primary frequency standards and as the basis of PTB᾽s time scale for a long time. Exhaustive investigations have now allowed the uncertainties of these two clocks to be reduced by a factor of 5 (CSF1) and 2.4 (CSF2). With relative uncertainties of 2.7 ⋅ 10–16 reached for CSF1 and 1.7 ⋅ 10–16 for CSF2, these two clocks range...

[ more ]
cture of the JAWS chip with 3000 integrated Josephson junctions and of the photodiode chip carrier (PDCC) connected to the optical waveguide.

At PTB, a pulse-driven Josephson standard for the generation of AC voltages has been realized where the voltage pulses are synthesized by means of optical components. This has advantages compared to the conventional operating procedure where the driving voltage pulses are conducted onto the superconducting chip via RF conductors.

[ more ]
Left: Color-coded spatial distribution of the electron temperature <em>T</em><sub>e</sub> in the nanostructures. Center: SEM cross-sectional image of the nanostructure. Right: Electron density distribution <em>n</em><sub>e</sub>. The false color representations left and right show the results of simulations.

Within the scope of a research consortium, researchers from PTB have succeeded in advancing as far as to reach a new regime of relativistic light/matter interaction. In the context of a compact laboratory experiment, extremely hot and dense plasmas were generated. These plasmas open up new perspectives for experiments on laser-induced nuclear physics and laboratory astrophysics.

[ more ]
Inlet of an integrating sphere

Integrating spheres are used to measure luminous flux; the same applies to the transmission measurement of microscope lenses. These transmission measurements can now be made more accurate thanks to a new additional element. The special insert developed at PTB serves as an adaptor between the aperture of the integrating sphere and the lens. Thanks to the insert, the lens is no longer in the...

[ more ]
The calorimetric water-cooled modules fully enclose the battery cell and ensure good thermal contact.

Battery cells must be tested with regard to their efficiency and operational reliability from the designing phase to the production process. For the thermal monitoring of batteries, a modular calorimeter has been developed at PTB. It consists of a variable number of practically identical components and allows the most diverse battery cell sizes to be examined. The modules are easily scalable with...

[ more ]
Angle measurement using an autocollimator

To measure small angular changes in objects, autocollimators are used. The detector used for this purpose, often a two-dimensional CCD sensor, is illuminated by a linear reticle pattern. Its position on the sensor is detected and has a limited resolution due to the pixel size. In the new procedure, this reticle is projected onto the sensor at an angle set specifically for this sensor, relative to...

[ more ]

Awards

Oliver Hupe Oliver HupeThe Head of Working Group 6.31, “Photon Dosimetry”, was elected to the Council at the EURADOS Annual Meeting 2019. He will be a treasurer on the Executive Board. The European Radiation Dosimetry Group (EURADOS e. V.) is a network of more than 70 European institutions and 600 scientists.

Richard Lange Richard LangeThe doctoral candidate at Department 4.4, “Time and Frequency”, won the renowned...

[ more ]
Die deutsche Delegation in Peking. Mit dabei waren der Nobelpreisträger Klaus von Klitzing, PTB-Präsident Joachim Ullrich, PTB-Vizepräsident Roman Schwartz sowie der ehemalige PTB-Präsident Ernst O. Göbel.

Forty years of successful cooperation between Germany and China were celebrated during a three-day official ceremony in Peking and sent on to the next stage: On 21 August, representatives of the Federal Ministry for Economic Affairs and Energy (BMWi) and the Chinese State Administration for Market Regulation (SAMR) signed a memorandum of understanding concerning the continuation of the cooperation...

[ more ]

Medical data which can be life-saving in the case of an accident have so far been saved at different places and independently of each other. A project which is initially planned for three years and is funded by the Lower Saxony Ministry of Research and the Volkswagen Foundation with a budget of 1.2 million euros is intended to change that. In the project, TU Braunschweig, MHH (Hannover Medical...

[ more ]

A new EURAMET metrology network called "Smart Electricity Grids" is dedicated to coordinating research activities related to intelligent power grids and establishing a sustainable European metrology research structure in this field. PTB is participating in operative efforts and is represented in the governing committees of the network.

[ more ]

A further new EURAMET network is intended to establish Europe-wide uniform structures related to quality assurance in laboratory medicine and to guarantee the metrological traceability of important quantities in this field. In this way, the requirements of a new EU regulation on in-vitro diagnostics will be implemented.

[ more ]

No secrets

Hardware components of an open-source low-field MRI scanner: pulse generator, high-frequencyamplifier, emitter/receiver switch with receiver pre-amplifier, excitation coil, gradient amplifier, x-, yandz-gradient coils for spatial encoding and MR magnets with field-homogenization inserts. A headphantom serves to illustrate the dimensions. The structural design plans will be published and madeaccessible to everyone for free; they will also be released for non-exclusive (even commercial) use.

Within the scope of an international cooperation project, PTB is participating in the development of a low-cost MRI scanner whose technological details will all be published as open-source hardware (OSH). The first images recorded by means of such OSH-MRI scanners are now available.

[ more ]
Schematic representation of the fluorescence excitation of a nanostructureconsisting of atoms of different elements (A, B, C). When excitation iseffected with an X-ray beam (E<sub>0</sub>) characteristic fluorescence radiation (E<sub>1</sub>, E<sub>2</sub>) is emitted.

Methods for the element-specific reconstruction of periodically nanostructured surfaces have been optimized at PTB. Such surfaces are used to manufacture ultra-modern integrated circuits. Measurements have shown that it is possible to characterize the spatial distribution of different atoms in nanostructures by analyzing X-ray fluorescence radiation.

[ more ]
Berkovich tip on a silicon AFM cantilever (large image), together with the ideal dimensions of a Berkovich tip (top left) and a lateral view of the manufactured tip (top right). The angular aperture is (143 ± 0.5)<sup>°</sup>, which is in good agreement with the definition of tips stated in the ISO standard. The effective tip height is approx. 1 μm and is thus sufficient for mechanical measurements close to the surface, e.g. for determining the indentation-depth-dependent electromechanical behavior of nanoscale semiconducting materials.

The novel picoindenter ‘made at PTB’ uses the tip of an atomic force microscope (AFM) as an indenter to characterize nanomaterials dimensionally and mechanically. This indenter has now been considerably enhanced: in the Laboratory for Emerging Nanometrology (LENA), a focused ion beam was used to produce pyramidal Berkovich tips on AFM cantilevers which can also be used in the picoindenter....

[ more ]
Schematic representation of the molecule-based single-photon source for applications in quantum radiometry, for example to calibrate a single-photon detector (1, SPAD) via a reference detector (2, analog). The value of g(2)(0) = 0.08 means there is a very small probability that two photons may be emitted at the same time. DBT: dibenzoterrylene.(© Pietro Lombardi)

Single-photon sources are so-called nonclassical light sources. In contrast to lasers or incandescent lamps, these sources emit light only as single quanta (photons). Applications of such sources are found in many areas of quantum technologies such as quantum-based imaging, quantum computing, quantum key distribution and quantum-enhanced optical measurements. Moreover, they are ideal for certain...

[ more ]
Schematic diagram (strongly simplified) of a Josephson impedance bridge combined with a quantum Hall resistor (QHR). The current for the measurement is supplied by two current sources (left and right); voltage is measured in a quantum-based way via two pulse-operated Josephson voltage standards (U<sub>1</sub> and U<sub>2</sub>). After aligning the bridge by adjusting the voltage ratios and phase angles, the voltage measured by the detector is zero; thus, the ratio of the impedances of the device under test (Z<sub>DUT</sub>) to those of the quantum Hall impedance standard (Z<sub>QHR</sub>) is equal to the ratio between the two bridge voltages U<sub>1</sub> and U<sub>2</sub> which is very precisely known.

Within the scope of a European metrology research project, PTB is investigating the utilizability of novel quantum Hall resistance standards based on graphene for impedance metrology. The activities aim to develop quantum-based impedance bridges to simplify the calibration of electrical AC voltage quantities for practice-oriented, flexible and efficient use, e.g. in calibration laboratories or in...

[ more ]
Overview of the database's contents. Each entry corresponds to a row in the table from top to bottom in the chronological order. Black pixels show availablevalues; white pixels indicate missing values.

A database developed at PTB provides more than 20 000 ECG images, machine-readable diagnostic findings and comments of cardiologists. This database was prepared primarily for the development of machine learning and is structured into training and test sections for comparability. The database, named PTB-XL, is publicly available at PhysioNet.

[ more ]
The optical inspection channel (yellow) allows the detection of the fluid level which arises around the vertical piston (gray).

To calibrate very small flowrates (< 0.1 ml/min), PTB is currently setting up a piston system to determine the volumetric flowrate. In this system, a liquid can be applied above the seal of the vertically moving piston with a low vapor pressure. The uncertainties normally inherent to this measurement process due to thermal inputs are minimized. An optical channel also allows leakages in the system...

[ more ]

Emitter and receiver antennas of future communication systems in the millimeter wave band and terahertz frequency range have to be oriented exactly towards each other to be able to communicate with each other. A new concept elaborated by PTB plans to combine two very high frequency omnidirectional radio range beacons that are oriented orthogonally to each other and are similar to those used in...

[ more ]
The two point light sources (fiber optics) are located on the object in motion. The image sensor registers the interference pattern whose orientation indicates the roll angle.

PTB has developed a cost-efficient and very simple procedure to measure roll angles in high-precision translation stages in optical metrology and industrial production. This procedure is based on two single-mode fiber optics and a conventional image sensor and requires no further optics. The two ends of the fiber optics whose ends have a fixed position to each other are located on the object in...

[ more ]

Awards

Fabian Wolf , a staff member of the QUEST Institute at PTB, was honored with the “Carl Zeiss Award for Young Researchers”. With this prize, the Ernst Abbe Fund, a member of the Stifterverband für die Deutsche Wissenschaft (Donors’ Association for the Promotion of Science and Humanities in Germany), is recognizing Wolf's work on motional Fock states for quantum-enhanced amplitude and phase...

[ more ]

Dr.-Ing. Prof. h.c. Frank Härtig ist neuer Vizepräsident der PTB. Er löst damit Hon.-Prof. Dr. Roman Schwartz ab, der das Amt sechs Jahre lang innehatte. 

[ more ]

A research association made up of Leibnitz Universität Hannover (LUH), TU Braunschweig, TU Clausthal, Jade Hochschule Wilhelmshaven and PTB has been receiving support from the Federal State of Lower Saxony since July 2020 initially for 15 months to set up an innovation laboratory for hydrogen technology. After a conceptual phase, the most successful innovation laboratories will be selected for a...

[ more ]

The German Research Foundation (Deutsche Forschungsgemeinschaft, DFG) is extending the Collaborative Research Center of the Leibniz Universität Hannover and PTB, “Designed Quantum States of Matter (DQ-mat) – generation, manipulation and detection for metrological applications and tests of fundamental physics”, for another four years with approximately 9.2 million euros in funding. (Contact: Piet...

[ more ]
Bereits jetzt sind große europäische Forschungszentren über ein Glasfaser-Netzwerk verbunden, in das hochgenaue Atomuhren Laserlicht einspeisen. (Abb.: Stefan Schröder/Uni Bonn)

A consortium of European National Metrology Institutes, the University of Bonn and highly specialized companies which shall be called “Clock Optical Network Services – Design Study” (CLONETS-DS) is to develop a design study for a future network for the distribution of high-precision optical frequencies and time signals starting on 1 October. The European Union will fund the project with 3 million...

[ more ]

On behalf of the German Federal Ministry for Economic Cooperation and Development (BMZ), PTB has been supporting the establishment of quality infrastructure in emerging and developing countries for about 60 years. In May 2020, BMZ and PTB ratified a new agreement which significantly expands PTB's task. The volume for establishing quality infrastructure in countries partnered with German...

[ more ]

PTB-News 3.2019PTB-News 3.2019

Sample with atomic step heights, recorded with a confocal laser scanning microscope. Each of theterraces is an atomically smooth lattice plane of the silicon (111) crystal with a constant step heightof h ≈ 0.314 nm.

In the course of the revision of the International System of Units (SI), which entered into force on 20 May 2019, the international Metre Convention, upon a proposal from the Consultative Committee for Length (CCL), endorsed the use of the lattice parameter of the silicon crystal (i.e. the spacing between the atomic layers) as a basis of the secondary realization of the meter in the nanometer...

[ more ]
The OTT system uses terminals for feeding in the data and at the target location. For remote locations, a number of bidirectional, inline optical amplifiers are used to compensate for signal attenuation in the fiber.

Each mobile telecommunications network requires synchronization between its components. Deutsche Telekom Technik AG has decided to test a method developed by the AGH University of Science and Technology in Krakow, Poland, for the future monitoring of selected points in its network. It is based on optical time transmission (OTT), which has been tested in cooperation with PTB, among others, on glass...

[ more ]
Demonstrating coherently elevated emission: after a full revolution around the storage ring (which takes 160 ns), the emission of the electron bunch microstructured by the laser radiation measured with a photodiode is clearly more intense.

In cooperation with the Helmholtz-Zentrum Berlin (HZB) and Tsinghua University Beijing, it has been successfully demonstrated at the Metrology Light Source (MLS), PTB's electron storage ring in Berlin, that the first step of so-called steady-state microbunching (SSMB) is feasible. This paves the way for future synchrotron radiation sources with higher intensities.

[ more ]
Typical measurement setup at PTB for the measurement of planar scattering parameters: on-wafer microwave probes over test structures on a silicon wafer.

PTB has provided evidence that on-wafer calibration structures manufactured on commercially available substrates may be used as transfer standards for reference calibrations. This will enable traceable planar scattering measurements in industrial applications for the first time.

[ more ]
The new device consists of a hemisphere on which 15 individual spectrometers are arranged in such a way that 15 different solid angles can be measured simultaneously. In this way, it is possible to determine the main direction of incidence of the X-ray photons on a person and, in particular, on an eye lens at the same time, so that the time it takes to characterize a workplace during running operation in a hospital is limited to the absolute minimum.

After the commencement of the Radiation Protection Act (StrlSchG) on 31 December 2018, the limit values for the dose to the eye lens have been considerably reduced. In order to prove and comply with these new limit values reliably, it is necessary to assess whether the existing radiation protection measures are sufficient and whether additional monitoring of the staff is required. A suitable...

[ more ]
Test sample with magnetic structures used for the measurements performed within the scope of the interlaboratory comparison. The light green areas consist of a magnetic layer; in the darker areas, this layer was removed by means of lithography.

So far, no internationally standardized measurement procedures have been available to measure magnetic field distributions that vary spatially on the nanometer scale. The NanoMag EMPIR metrology research project, which was spearheaded by PTB and has recently been completed with success, bridges this gap and will allow internationally comparable measurements of magnetic field distributions with...

[ more ]
Measuring setup with sensors on a fork-like structure, accommodated at the equator of the sphere.

Nearly perfect spheres are used in various branches of industry, such as optics or industrial metrology. Conventional procedures to measure form error are, however, much too slow and tedious for the industrial manufacturing of such spheres. A new measuring device developed by PTB is reliable and more economical than existing systems and provides fast results. This device consists of two collinear...

[ more ]
Experimental model of a Planck-Balance.

The high-precision Planck-Balance, developed by PTB in cooperation with TU Ilmenau, measures over a continuous mass range and works according to the principle of electromagnetic force compensation. To put it more simply: a weight placed on the one side of the balance for weighing is compensated for on the other side by an electric force. This electric force is inextricably linked to Planck᾽s...

[ more ]
Diagrammatic sketch of the double-pass AOM prototype

Acousto-optic modulator systems (AOMs) are used to modulate the frequency and the intensity of laser radiation. If a beam passes twice through an AOM, this allows the frequency shift to be doubled while at the same time suppressing the primary beam frequency adequately. Such a setup is called a double-pass arrangement. Our new PTB design is based on a specific convolution of the beam path for use...

[ more ]

Faster, further, better – this development will continue even after 5G is introduced. A DFG project called “Metrology for THz communications” (Meteracom) is researching what concepts could look like for even higher transmission rates. The focus is on the terahertz frequency range in which more than 100 gigabits could be transferred per second in the future. That is approximately ten to one hundred...

[ more ]
Eine Ampel mit den Farben rot, orange, gelb und grün.

PTB has implemented numerous measures to fight the coronavirus (SARSCoV- 2); for example, nearly all events planned for the near future have been cancelled, as have official trips – including those between PTB’s sites. All staff members working on site at PTB Braunschweig and PTB Berlin must follow strict hygiene and conduct regulations. Lastly, most PTB staff members are now working from home....

[ more ]
Trial of a dental drilling guide produced by additive manufacturing for the drilling of holes to fit dental implants into artificial jaw models with only few abutment teeth. The drilling angle α and the drilling depth were measured by means of computed tomography

Medicine is placing high expectations on implants and auxiliary materials that are manufactured specifically for each individual patient. This can be done by means of additive manufacturing (3D printing), which allows nearly any complex shape to be produced. Before starting to use such implants widely, the medical sector and certification bodies demand proof of the fact that their high quality is...

[ more ]
Schematic setup of virtual mammography

Within the scope of the mammography screening program, approved devices must ensure that radiologists are able to reliably detect even small contrasts. The imaging quality of each device is therefore checked every year by means of monitoring measurements. For this purpose, test images of phantoms are taken and assessed by means of procedures of data analysis. PTB has developed a simulation...

[ more ]
The OBCA mounted next to the transfer standard on the translation system at PTB's Reduced Background Calibration Facility 2. (Photo credit: Fraunhofer IOF, CYMER)

At PTB, the reference radiation source of the EnMAP satellite for the remote sensing of the Earth has been calibrated with high resolution. This ensures the long-term comparability and traceability of its global measurement data from the fields of geobiology, geochemistry and geophysics.

[ more ]
PTB's caesium fountain clocks CSF2 (in the foreground) and CSF1. The atoms are cooled by lasers in the lower part of the vacuum setup and then launched upwards. In the upper part of the setup, they are irradiated with microwaves during their flight.

PTB's two caesium fountain clocks, CSF1 and CSF2, have been established as primary frequency standards and as the basis of PTB᾽s time scale for a long time. Exhaustive investigations have now allowed the uncertainties of these two clocks to be reduced by a factor of 5 (CSF1) and 2.4 (CSF2). With relative uncertainties of 2.7 ⋅ 10–16 reached for CSF1 and 1.7 ⋅ 10–16 for CSF2, these two clocks range...

[ more ]
cture of the JAWS chip with 3000 integrated Josephson junctions and of the photodiode chip carrier (PDCC) connected to the optical waveguide.

At PTB, a pulse-driven Josephson standard for the generation of AC voltages has been realized where the voltage pulses are synthesized by means of optical components. This has advantages compared to the conventional operating procedure where the driving voltage pulses are conducted onto the superconducting chip via RF conductors.

[ more ]
Left: Color-coded spatial distribution of the electron temperature <em>T</em><sub>e</sub> in the nanostructures. Center: SEM cross-sectional image of the nanostructure. Right: Electron density distribution <em>n</em><sub>e</sub>. The false color representations left and right show the results of simulations.

Within the scope of a research consortium, researchers from PTB have succeeded in advancing as far as to reach a new regime of relativistic light/matter interaction. In the context of a compact laboratory experiment, extremely hot and dense plasmas were generated. These plasmas open up new perspectives for experiments on laser-induced nuclear physics and laboratory astrophysics.

[ more ]
Inlet of an integrating sphere

Integrating spheres are used to measure luminous flux; the same applies to the transmission measurement of microscope lenses. These transmission measurements can now be made more accurate thanks to a new additional element. The special insert developed at PTB serves as an adaptor between the aperture of the integrating sphere and the lens. Thanks to the insert, the lens is no longer in the...

[ more ]
The calorimetric water-cooled modules fully enclose the battery cell and ensure good thermal contact.

Battery cells must be tested with regard to their efficiency and operational reliability from the designing phase to the production process. For the thermal monitoring of batteries, a modular calorimeter has been developed at PTB. It consists of a variable number of practically identical components and allows the most diverse battery cell sizes to be examined. The modules are easily scalable with...

[ more ]
Angle measurement using an autocollimator

To measure small angular changes in objects, autocollimators are used. The detector used for this purpose, often a two-dimensional CCD sensor, is illuminated by a linear reticle pattern. Its position on the sensor is detected and has a limited resolution due to the pixel size. In the new procedure, this reticle is projected onto the sensor at an angle set specifically for this sensor, relative to...

[ more ]

Awards

Oliver Hupe Oliver HupeThe Head of Working Group 6.31, “Photon Dosimetry”, was elected to the Council at the EURADOS Annual Meeting 2019. He will be a treasurer on the Executive Board. The European Radiation Dosimetry Group (EURADOS e. V.) is a network of more than 70 European institutions and 600 scientists.

Richard Lange Richard LangeThe doctoral candidate at Department 4.4, “Time and Frequency”, won the renowned...

[ more ]
Die deutsche Delegation in Peking. Mit dabei waren der Nobelpreisträger Klaus von Klitzing, PTB-Präsident Joachim Ullrich, PTB-Vizepräsident Roman Schwartz sowie der ehemalige PTB-Präsident Ernst O. Göbel.

Forty years of successful cooperation between Germany and China were celebrated during a three-day official ceremony in Peking and sent on to the next stage: On 21 August, representatives of the Federal Ministry for Economic Affairs and Energy (BMWi) and the Chinese State Administration for Market Regulation (SAMR) signed a memorandum of understanding concerning the continuation of the cooperation...

[ more ]

Medical data which can be life-saving in the case of an accident have so far been saved at different places and independently of each other. A project which is initially planned for three years and is funded by the Lower Saxony Ministry of Research and the Volkswagen Foundation with a budget of 1.2 million euros is intended to change that. In the project, TU Braunschweig, MHH (Hannover Medical...

[ more ]

A new EURAMET metrology network called "Smart Electricity Grids" is dedicated to coordinating research activities related to intelligent power grids and establishing a sustainable European metrology research structure in this field. PTB is participating in operative efforts and is represented in the governing committees of the network.

[ more ]

A further new EURAMET network is intended to establish Europe-wide uniform structures related to quality assurance in laboratory medicine and to guarantee the metrological traceability of important quantities in this field. In this way, the requirements of a new EU regulation on in-vitro diagnostics will be implemented.

[ more ]

PTB-News 3.2019PTB-News 3.2019

Trial of a dental drilling guide produced by additive manufacturing for the drilling of holes to fit dental implants into artificial jaw models with only few abutment teeth. The drilling angle α and the drilling depth were measured by means of computed tomography

Medicine is placing high expectations on implants and auxiliary materials that are manufactured specifically for each individual patient. This can be done by means of additive manufacturing (3D printing), which allows nearly any complex shape to be produced. Before starting to use such implants widely, the medical sector and certification bodies demand proof of the fact that their high quality is...

[ more ]
Schematic setup of virtual mammography

Within the scope of the mammography screening program, approved devices must ensure that radiologists are able to reliably detect even small contrasts. The imaging quality of each device is therefore checked every year by means of monitoring measurements. For this purpose, test images of phantoms are taken and assessed by means of procedures of data analysis. PTB has developed a simulation...

[ more ]
The OBCA mounted next to the transfer standard on the translation system at PTB's Reduced Background Calibration Facility 2. (Photo credit: Fraunhofer IOF, CYMER)

At PTB, the reference radiation source of the EnMAP satellite for the remote sensing of the Earth has been calibrated with high resolution. This ensures the long-term comparability and traceability of its global measurement data from the fields of geobiology, geochemistry and geophysics.

[ more ]
PTB's caesium fountain clocks CSF2 (in the foreground) and CSF1. The atoms are cooled by lasers in the lower part of the vacuum setup and then launched upwards. In the upper part of the setup, they are irradiated with microwaves during their flight.

PTB's two caesium fountain clocks, CSF1 and CSF2, have been established as primary frequency standards and as the basis of PTB᾽s time scale for a long time. Exhaustive investigations have now allowed the uncertainties of these two clocks to be reduced by a factor of 5 (CSF1) and 2.4 (CSF2). With relative uncertainties of 2.7 ⋅ 10–16 reached for CSF1 and 1.7 ⋅ 10–16 for CSF2, these two clocks range...

[ more ]
cture of the JAWS chip with 3000 integrated Josephson junctions and of the photodiode chip carrier (PDCC) connected to the optical waveguide.

At PTB, a pulse-driven Josephson standard for the generation of AC voltages has been realized where the voltage pulses are synthesized by means of optical components. This has advantages compared to the conventional operating procedure where the driving voltage pulses are conducted onto the superconducting chip via RF conductors.

[ more ]
Left: Color-coded spatial distribution of the electron temperature <em>T</em><sub>e</sub> in the nanostructures. Center: SEM cross-sectional image of the nanostructure. Right: Electron density distribution <em>n</em><sub>e</sub>. The false color representations left and right show the results of simulations.

Within the scope of a research consortium, researchers from PTB have succeeded in advancing as far as to reach a new regime of relativistic light/matter interaction. In the context of a compact laboratory experiment, extremely hot and dense plasmas were generated. These plasmas open up new perspectives for experiments on laser-induced nuclear physics and laboratory astrophysics.

[ more ]
Inlet of an integrating sphere

Integrating spheres are used to measure luminous flux; the same applies to the transmission measurement of microscope lenses. These transmission measurements can now be made more accurate thanks to a new additional element. The special insert developed at PTB serves as an adaptor between the aperture of the integrating sphere and the lens. Thanks to the insert, the lens is no longer in the...

[ more ]
The calorimetric water-cooled modules fully enclose the battery cell and ensure good thermal contact.

Battery cells must be tested with regard to their efficiency and operational reliability from the designing phase to the production process. For the thermal monitoring of batteries, a modular calorimeter has been developed at PTB. It consists of a variable number of practically identical components and allows the most diverse battery cell sizes to be examined. The modules are easily scalable with...

[ more ]
Angle measurement using an autocollimator

To measure small angular changes in objects, autocollimators are used. The detector used for this purpose, often a two-dimensional CCD sensor, is illuminated by a linear reticle pattern. Its position on the sensor is detected and has a limited resolution due to the pixel size. In the new procedure, this reticle is projected onto the sensor at an angle set specifically for this sensor, relative to...

[ more ]

Awards

Oliver Hupe Oliver HupeThe Head of Working Group 6.31, “Photon Dosimetry”, was elected to the Council at the EURADOS Annual Meeting 2019. He will be a treasurer on the Executive Board. The European Radiation Dosimetry Group (EURADOS e. V.) is a network of more than 70 European institutions and 600 scientists.

Richard Lange Richard LangeThe doctoral candidate at Department 4.4, “Time and Frequency”, won the renowned...

[ more ]
Die deutsche Delegation in Peking. Mit dabei waren der Nobelpreisträger Klaus von Klitzing, PTB-Präsident Joachim Ullrich, PTB-Vizepräsident Roman Schwartz sowie der ehemalige PTB-Präsident Ernst O. Göbel.

Forty years of successful cooperation between Germany and China were celebrated during a three-day official ceremony in Peking and sent on to the next stage: On 21 August, representatives of the Federal Ministry for Economic Affairs and Energy (BMWi) and the Chinese State Administration for Market Regulation (SAMR) signed a memorandum of understanding concerning the continuation of the cooperation...

[ more ]

Medical data which can be life-saving in the case of an accident have so far been saved at different places and independently of each other. A project which is initially planned for three years and is funded by the Lower Saxony Ministry of Research and the Volkswagen Foundation with a budget of 1.2 million euros is intended to change that. In the project, TU Braunschweig, MHH (Hannover Medical...

[ more ]

A new EURAMET metrology network called "Smart Electricity Grids" is dedicated to coordinating research activities related to intelligent power grids and establishing a sustainable European metrology research structure in this field. PTB is participating in operative efforts and is represented in the governing committees of the network.

[ more ]

A further new EURAMET network is intended to establish Europe-wide uniform structures related to quality assurance in laboratory medicine and to guarantee the metrological traceability of important quantities in this field. In this way, the requirements of a new EU regulation on in-vitro diagnostics will be implemented.

[ more ]
Artistic representation of the ion pair: laser cooled Be<sup>+</sup> (top right) and highly charged Ar<sup>13+</sup> (bottom left)

In cooperation with the Max Planck Institute for Nuclear Physics in Heidelberg, the QUEST Institute at PTB has succeeded for the first time in performing precision spectroscopy on highly charged ions. This pioneering experiment makes the field of highly charged ions accessible for research on novel atomic clocks and tests of fundamental physics.

[ more ]
In the single-particle counter, the suspension is injected with a cannula into the conical area of the flow-through cell and then accelerated through the taper and the surrounding sheath flow. In this way, the particles are separated along the direction of flow and mostly pass through the laser focus one by one. For each particle, the stray light is measured in the direction of the laser beam (forward scattering) and perpendicular to it (sideward scattering).

Within the framework of a technology transfer project, an optical singleparticle counter has been developed at PTB to detect and determine the size of micro- and nanoparticles in suspension. The resulting prototype covers a dynamic measuring range that allows polystyrene particles from 80 nm to 8 μm in diameter to be detected.

[ more ]
Decay chain of thorium-227. The particularity of thorium, which consists in thorium generating mainly alpha decay, is clearly visible here.

For the first time, PTB has succeeded in determining the specific activity of a thorium-227 solution very accurately by means of liquid scintillation counters. This means that traceable activity measurements of this radionuclide, which is being tested for radioimmunotherapy in nuclear medicine, are now possible. Also, the half-life of thorium-227 was determined by means of two measurement methods.

[ more ]
Left: Conventional pressure measurement with a pressure balance according to <em>p</em><sub>PB</sub> = <em>F<sub>g</sub></em>/A<sub>eff</sub> (PB: pressure balance; g: gravitational force; A<sub>eff</sub>: effective surface of a piston/cylinder system). Right: The new electrical approach: the relative change in capacitance <em>C</em>(<em>T</em>) caused by the measuring gas at a known temperature <em>T</em>, which is determined by means of a calibrated resistance thermometer <em>R</em>(<em>T</em>), can be directly linked to the gas pressure. The dielectric constant and the interaction of the gas particles enter into the requiredab initio calculations: <em>p</em><sub>ab-initio</sub>(<em>C</em>,<em>T</em>, Gas<sub>ab-initio</sub>)

Within the scope of the work on the redefinition of the base unit kelvin, PTB developed a new method for pressure measurement based on the capacitance measurement of helium gas. From the first attempt, it was almost as good as the world᾽s best method for pressure measurement with a piston manometer.

[ more ]
Wind turbines and PTB's flying measurement platform.

For the first time worldwide, PTB has succeeded in showing how, to what extent and under which conditions wind turbines influence the signal integrity of air navigation systems. These findings have made a forecasting tool possible that could speed up the decision- making process for hundreds of building applications that are stuck in the ”approval backlog“.

[ more ]
Left: Representation of a multiradius surface. For illustration purposes, the spherical segments of the surface have been raised. Right: Photo of a realization. The diameter is 40 mm.

Non-spherical optical surfaces, i.e. aspheres and freeform surfaces, are nowadays essential components of many modern imaging systems in industry and research. To test high-precision measuring instruments for the measurement of aspheres and freeform surfaces, special reference surfaces have been developed which consist of several spherical segments with differing radii. The first prototypes have...

[ more ]
Result of the electrothermal removal of a via

Thin-film sensors enable the high-precision and spatially resolved measurement of various physical states, especially in particularly small places that are difficult to access, and under harsh environmental conditions. In thin-film sensor production, possible defects such as vias caused by pinholes in the insulation are particularly unwelcome as they may make the thin-film sensors applied useless....

[ more ]
Aspherical lens shape

New challenges are arising for modern optical measuring systems with regard to the simulation and optimization of the measuring systems and assessment procedures. This is particularly true of form measurement systems for aspheres, freeform surfaces and the simulation of optical systems such as those used in modern camera systems, and complex optical measuring systems. Optimizing procedures which...

[ more ]
Ein Prototyp des Detektors, installiert am 50-MeV-Forschungsbeschleuniger MELAF bei der PTB-Braunschweig

A detector developed at PTB measures the mean energy and charge of charged particles. These measurements are pulseresolved and take place in real time. The device, which delivers up to 10 measurements per second, is also suitable for continuous ion radiation and electron radiation . Moreover , its principle allows the energy of particle radiation of very low intensity to be determined. The device...

[ more ]

Awards

Rudolf Meeß, Thomas Wiedenhöfer, Frank Härtig and Katharina Lehrmann The team of PTB scientists was awarded the Technology Transfer Prize of the Chamber of Industry and Commerce of Braunschweig for successfully passing on a masterpiece of metrological and product engineering from research to industry, namely ultrapure, extremely round silicon spheres which represent the new definition of the...

[ more ]

Für die Entwicklung einer völlig neuen Atomuhr haben PTB-Forscher zusammen mit internationalen Kollegen einen prestigeträchtigen Synergy Grant des europäischen Forschungsrates ERC eingeworben. Ziel des Projektes, das für sechs Jahre mit insgesamt 13,8 Millionen Euro gefördert wird, ist die Entwicklung eines völlig neuen Typs Atomuhr:

[ more ]

PTB-News 3.2019PTB-News 3.2019

Trial of a dental drilling guide produced by additive manufacturing for the drilling of holes to fit dental implants into artificial jaw models with only few abutment teeth. The drilling angle α and the drilling depth were measured by means of computed tomography

Medicine is placing high expectations on implants and auxiliary materials that are manufactured specifically for each individual patient. This can be done by means of additive manufacturing (3D printing), which allows nearly any complex shape to be produced. Before starting to use such implants widely, the medical sector and certification bodies demand proof of the fact that their high quality is...

[ more ]
Schematic setup of virtual mammography

Within the scope of the mammography screening program, approved devices must ensure that radiologists are able to reliably detect even small contrasts. The imaging quality of each device is therefore checked every year by means of monitoring measurements. For this purpose, test images of phantoms are taken and assessed by means of procedures of data analysis. PTB has developed a simulation...

[ more ]
The OBCA mounted next to the transfer standard on the translation system at PTB's Reduced Background Calibration Facility 2. (Photo credit: Fraunhofer IOF, CYMER)

At PTB, the reference radiation source of the EnMAP satellite for the remote sensing of the Earth has been calibrated with high resolution. This ensures the long-term comparability and traceability of its global measurement data from the fields of geobiology, geochemistry and geophysics.

[ more ]
PTB's caesium fountain clocks CSF2 (in the foreground) and CSF1. The atoms are cooled by lasers in the lower part of the vacuum setup and then launched upwards. In the upper part of the setup, they are irradiated with microwaves during their flight.

PTB's two caesium fountain clocks, CSF1 and CSF2, have been established as primary frequency standards and as the basis of PTB᾽s time scale for a long time. Exhaustive investigations have now allowed the uncertainties of these two clocks to be reduced by a factor of 5 (CSF1) and 2.4 (CSF2). With relative uncertainties of 2.7 ⋅ 10–16 reached for CSF1 and 1.7 ⋅ 10–16 for CSF2, these two clocks range...

[ more ]
cture of the JAWS chip with 3000 integrated Josephson junctions and of the photodiode chip carrier (PDCC) connected to the optical waveguide.

At PTB, a pulse-driven Josephson standard for the generation of AC voltages has been realized where the voltage pulses are synthesized by means of optical components. This has advantages compared to the conventional operating procedure where the driving voltage pulses are conducted onto the superconducting chip via RF conductors.

[ more ]
Left: Color-coded spatial distribution of the electron temperature <em>T</em><sub>e</sub> in the nanostructures. Center: SEM cross-sectional image of the nanostructure. Right: Electron density distribution <em>n</em><sub>e</sub>. The false color representations left and right show the results of simulations.

Within the scope of a research consortium, researchers from PTB have succeeded in advancing as far as to reach a new regime of relativistic light/matter interaction. In the context of a compact laboratory experiment, extremely hot and dense plasmas were generated. These plasmas open up new perspectives for experiments on laser-induced nuclear physics and laboratory astrophysics.

[ more ]
Inlet of an integrating sphere

Integrating spheres are used to measure luminous flux; the same applies to the transmission measurement of microscope lenses. These transmission measurements can now be made more accurate thanks to a new additional element. The special insert developed at PTB serves as an adaptor between the aperture of the integrating sphere and the lens. Thanks to the insert, the lens is no longer in the...

[ more ]
The calorimetric water-cooled modules fully enclose the battery cell and ensure good thermal contact.

Battery cells must be tested with regard to their efficiency and operational reliability from the designing phase to the production process. For the thermal monitoring of batteries, a modular calorimeter has been developed at PTB. It consists of a variable number of practically identical components and allows the most diverse battery cell sizes to be examined. The modules are easily scalable with...

[ more ]
Angle measurement using an autocollimator

To measure small angular changes in objects, autocollimators are used. The detector used for this purpose, often a two-dimensional CCD sensor, is illuminated by a linear reticle pattern. Its position on the sensor is detected and has a limited resolution due to the pixel size. In the new procedure, this reticle is projected onto the sensor at an angle set specifically for this sensor, relative to...

[ more ]

Awards

Oliver Hupe Oliver HupeThe Head of Working Group 6.31, “Photon Dosimetry”, was elected to the Council at the EURADOS Annual Meeting 2019. He will be a treasurer on the Executive Board. The European Radiation Dosimetry Group (EURADOS e. V.) is a network of more than 70 European institutions and 600 scientists.

Richard Lange Richard LangeThe doctoral candidate at Department 4.4, “Time and Frequency”, won the renowned...

[ more ]
Die deutsche Delegation in Peking. Mit dabei waren der Nobelpreisträger Klaus von Klitzing, PTB-Präsident Joachim Ullrich, PTB-Vizepräsident Roman Schwartz sowie der ehemalige PTB-Präsident Ernst O. Göbel.

Forty years of successful cooperation between Germany and China were celebrated during a three-day official ceremony in Peking and sent on to the next stage: On 21 August, representatives of the Federal Ministry for Economic Affairs and Energy (BMWi) and the Chinese State Administration for Market Regulation (SAMR) signed a memorandum of understanding concerning the continuation of the cooperation...

[ more ]

Medical data which can be life-saving in the case of an accident have so far been saved at different places and independently of each other. A project which is initially planned for three years and is funded by the Lower Saxony Ministry of Research and the Volkswagen Foundation with a budget of 1.2 million euros is intended to change that. In the project, TU Braunschweig, MHH (Hannover Medical...

[ more ]

A new EURAMET metrology network called "Smart Electricity Grids" is dedicated to coordinating research activities related to intelligent power grids and establishing a sustainable European metrology research structure in this field. PTB is participating in operative efforts and is represented in the governing committees of the network.

[ more ]

A further new EURAMET network is intended to establish Europe-wide uniform structures related to quality assurance in laboratory medicine and to guarantee the metrological traceability of important quantities in this field. In this way, the requirements of a new EU regulation on in-vitro diagnostics will be implemented.

[ more ]
Trial of a dental drilling guide produced by additive manufacturing for the drilling of holes to fit dental implants into artificial jaw models with only few abutment teeth. The drilling angle α and the drilling depth were measured by means of computed tomography

Medicine is placing high expectations on implants and auxiliary materials that are manufactured specifically for each individual patient. This can be done by means of additive manufacturing (3D printing), which allows nearly any complex shape to be produced. Before starting to use such implants widely, the medical sector and certification bodies demand proof of the fact that their high quality is...

[ more ]
Schematic setup of virtual mammography

Within the scope of the mammography screening program, approved devices must ensure that radiologists are able to reliably detect even small contrasts. The imaging quality of each device is therefore checked every year by means of monitoring measurements. For this purpose, test images of phantoms are taken and assessed by means of procedures of data analysis. PTB has developed a simulation...

[ more ]
The OBCA mounted next to the transfer standard on the translation system at PTB's Reduced Background Calibration Facility 2. (Photo credit: Fraunhofer IOF, CYMER)

At PTB, the reference radiation source of the EnMAP satellite for the remote sensing of the Earth has been calibrated with high resolution. This ensures the long-term comparability and traceability of its global measurement data from the fields of geobiology, geochemistry and geophysics.

[ more ]
PTB's caesium fountain clocks CSF2 (in the foreground) and CSF1. The atoms are cooled by lasers in the lower part of the vacuum setup and then launched upwards. In the upper part of the setup, they are irradiated with microwaves during their flight.

PTB's two caesium fountain clocks, CSF1 and CSF2, have been established as primary frequency standards and as the basis of PTB᾽s time scale for a long time. Exhaustive investigations have now allowed the uncertainties of these two clocks to be reduced by a factor of 5 (CSF1) and 2.4 (CSF2). With relative uncertainties of 2.7 ⋅ 10–16 reached for CSF1 and 1.7 ⋅ 10–16 for CSF2, these two clocks range...

[ more ]
cture of the JAWS chip with 3000 integrated Josephson junctions and of the photodiode chip carrier (PDCC) connected to the optical waveguide.

At PTB, a pulse-driven Josephson standard for the generation of AC voltages has been realized where the voltage pulses are synthesized by means of optical components. This has advantages compared to the conventional operating procedure where the driving voltage pulses are conducted onto the superconducting chip via RF conductors.

[ more ]
Left: Color-coded spatial distribution of the electron temperature <em>T</em><sub>e</sub> in the nanostructures. Center: SEM cross-sectional image of the nanostructure. Right: Electron density distribution <em>n</em><sub>e</sub>. The false color representations left and right show the results of simulations.

Within the scope of a research consortium, researchers from PTB have succeeded in advancing as far as to reach a new regime of relativistic light/matter interaction. In the context of a compact laboratory experiment, extremely hot and dense plasmas were generated. These plasmas open up new perspectives for experiments on laser-induced nuclear physics and laboratory astrophysics.

[ more ]
Inlet of an integrating sphere

Integrating spheres are used to measure luminous flux; the same applies to the transmission measurement of microscope lenses. These transmission measurements can now be made more accurate thanks to a new additional element. The special insert developed at PTB serves as an adaptor between the aperture of the integrating sphere and the lens. Thanks to the insert, the lens is no longer in the...

[ more ]
The calorimetric water-cooled modules fully enclose the battery cell and ensure good thermal contact.

Battery cells must be tested with regard to their efficiency and operational reliability from the designing phase to the production process. For the thermal monitoring of batteries, a modular calorimeter has been developed at PTB. It consists of a variable number of practically identical components and allows the most diverse battery cell sizes to be examined. The modules are easily scalable with...

[ more ]
Angle measurement using an autocollimator

To measure small angular changes in objects, autocollimators are used. The detector used for this purpose, often a two-dimensional CCD sensor, is illuminated by a linear reticle pattern. Its position on the sensor is detected and has a limited resolution due to the pixel size. In the new procedure, this reticle is projected onto the sensor at an angle set specifically for this sensor, relative to...

[ more ]

Awards

Oliver Hupe Oliver HupeThe Head of Working Group 6.31, “Photon Dosimetry”, was elected to the Council at the EURADOS Annual Meeting 2019. He will be a treasurer on the Executive Board. The European Radiation Dosimetry Group (EURADOS e. V.) is a network of more than 70 European institutions and 600 scientists.

Richard Lange Richard LangeThe doctoral candidate at Department 4.4, “Time and Frequency”, won the renowned...

[ more ]
Die deutsche Delegation in Peking. Mit dabei waren der Nobelpreisträger Klaus von Klitzing, PTB-Präsident Joachim Ullrich, PTB-Vizepräsident Roman Schwartz sowie der ehemalige PTB-Präsident Ernst O. Göbel.

Forty years of successful cooperation between Germany and China were celebrated during a three-day official ceremony in Peking and sent on to the next stage: On 21 August, representatives of the Federal Ministry for Economic Affairs and Energy (BMWi) and the Chinese State Administration for Market Regulation (SAMR) signed a memorandum of understanding concerning the continuation of the cooperation...

[ more ]

Medical data which can be life-saving in the case of an accident have so far been saved at different places and independently of each other. A project which is initially planned for three years and is funded by the Lower Saxony Ministry of Research and the Volkswagen Foundation with a budget of 1.2 million euros is intended to change that. In the project, TU Braunschweig, MHH (Hannover Medical...

[ more ]

A new EURAMET metrology network called "Smart Electricity Grids" is dedicated to coordinating research activities related to intelligent power grids and establishing a sustainable European metrology research structure in this field. PTB is participating in operative efforts and is represented in the governing committees of the network.

[ more ]

A further new EURAMET network is intended to establish Europe-wide uniform structures related to quality assurance in laboratory medicine and to guarantee the metrological traceability of important quantities in this field. In this way, the requirements of a new EU regulation on in-vitro diagnostics will be implemented.

[ more ]

PTB-News 2.2019PTB-News 2.2019

A tunable laser excites an extremely narrow-band resonance in an Yb<sup>+</sup> ion of an atomic clock. Two ions with wave functions (yellow) that are oriented at right angles are interrogated by means of laser light with an adjustable frequency shift Δf to measure a possible frequency difference. The whole experimental setup rotates together with the Earth once a day relative to the fixed stars.

The first long-term comparison of two optical ytterbium clocks has provided reliable results concerning their accuracy and stability at the limit of what has been measurable to date. At the same time, the Lorentz symmetry was confirmed for electrons in even tighter experimental limits.

[ more ]
Simultaneous changes in the air pressure (top) and in the relative angle measurement error of the autocollimator (bottom; ppm: parts per million) as a function of time.

High-precision angle measurements carried out by means of autocollimators are significantly influenced by the refractive index of air – and thus in particular by the ambient pressure. When comparing measurements that have been carried out at different locations, it is therefore necessary to take changes in pressure into account. PTB has developed suitable strategies both to correct the measurement...

[ more ]
Collector mirror for an EUVL plasma source, mounted on the sample goniometer inside PTB's EUV reflectometer (photo: Fraunhofer IOF, CYMER)

The announcement made by the large semiconductor manufacturers Samsung and TSMC in fall 2018 that they would start using EUV lithography (EUVL) to manufacture high-end processors marks the commercial breakthrough of this technology after a long research phase. For as many as 20 years, PTB has been supporting the development of projection lenses for EUVL by means of at-wavelength metrology with...

[ more ]
Over its surface of 2.40 m × 4.70 m, the LED-based solar simulator is equipped with a total of 16 320 LEDs. On the measurement plane, the colored light of the LEDs mixes to yield a spectrum similar to that of the sun.

PTB has recently started using an LEDbased solar simulator that is capable of varying the spectral composition, the brightness and the duration of the simulated solar irradiance independently of each other. The instrument thus provides decisive advantages over its conventional xenon counterparts. At PTB, solar modules can now be examined with a broad array of tests that are closer to real...

[ more ]
Measurement results of a nanomagnetic thin film carried out with the quantitative magnetic force microscope recently developed by PTB. a) The height profile of the thin-film surface is very smooth and only shows infinitesimal height differences in the range of a few nanometers. b): In contrast, the measuring signal exhibits meandering magnetic domains of approx. 200 nm in width.

A microscope for the imaging of magnetic nanostructures has been developed at PTB. This microscope allows the magnetic field distributions to be determined quantitatively for the first time with nanometer resolution over sample areas of up to a few centimeters.

[ more ]
The mobile measuring device for the non-invasive determination of the X-ray spectra and for the characterization of the bow-tie filters of a computed tomography system. In contrast to other comparable measurement methods, it is not necessary for the CT system to be in service mode. The measurements can be performed on the CT system in just a few minutes using the existing clinical scan protocols.

Depending on the type of examination performed, the radiation burden incurred by patients due to CT imaging can be considerable. PTB has developed a mobile measuring device aimed at indicating the individual effective dose of a patient on a CT display within just a few minutes after a scan. Within approximately two minutes, this device is able to determine the characteristics of the CT X-ray beam...

[ more ]
The new building accommodates, among other things, testing laboratories for exhaust meters that are state of the art and a calibration laboratory for particle counters.

The regular inspection of motor vehicle emissions became more stringent in several ways at the end of 2017. This required exhaustive research activities, and numerous type examination certificates for exhaust meters had to be issued or renewed promptly. For this purpose, a new building was planned, erected and commissioned within just one year in order to accommodate a new certification...

[ more ]
Piconewton transfer standard with the reference surface (1) and the contact body (2) that is moved by means of a comb drive (3).

Scanning force microscopes are used not only to measure nanostructures and fine roughness, but also as force sensors in pharmacy and in materials research. To measure force precisely, it is important to determine the bending stiffness of the cantilever with great accuracy. Until recently, suitable measurement procedures did not exist. PTB᾽s new transfer standard calibrates the smallest of forces...

[ more ]
Multilayer ion traps with thick-film dielectric medium (gray area). On the surface, the ions are kept in the inhomogeneous electric field of the trap structure.

Microstructured ion traps are the technological basis for a future quantum computer based on single ions as qubits. In such ion traps, ions are trapped by means of inhomogeneous electric fields above the surface. Several procedures developed by PTB for manufacturing multilayer thick-film structures with interconnects fulfill the stringent requirements set by the application. These procedures allow...

[ more ]

Until recently, size distributions and the wavelength-dependent refractive index of microparticles could only be determined with great effort. PTB has now developed a new procedure that simplifies such measurements. The spectral extinction cross section is derived from the transmission spectrum of particles in suspensions, emulsions or aerosols and is then analyzed by means of a mathematical...

[ more ]

On 20 May 2019, World Metrology Day, the revised International System of Units (SI) entered into force. On 16 November 2018, the revision was adopted unanimously by the representatives of all member states of the Metre Convention at the 26th General Conference on Weights and Measures (CGPM) held in Versailles. Since 20 May 2019, all SI units are based on a set of 7 defining natural constants....

[ more ]

The NanoMet Research Training Group, which has been managed jointly by TU Braunschweig and PTB since 2014, will be funded for another four and a half years by the Deutsche Forschungsgemeinschaft (DFG). Within the scope of this Research Training Group, doctoral theses on three topics from the field of nanometrology (“Complex Systems”, “Quantum Systems” and “Biological Systems”) have been mentored....

[ more ]

In 2018, PTB issued the first type-examination certificate for electric vehicle charging stations. This confirms that the stations meet all of the requirements of the measuring and verification legislation of Germany and not only guarantee exact measurements, but also a charging process that is transparent and comprehensible to the customers. This system also states explicitly when, where and how...

[ more ]

For the first time, three Smart Meter Gateways have obtained a type-examination certificate from PTB. The Smart Meter Gateway is a key technology for digitalization in the context of the energy transition. Together with a modern power meter, it forms a smart measuring system that will soon be playing a central role in the energy-supply industry. Complying with the most stringent data security and...

[ more ]

A new research initiative, the MGP/PTB/ RIKEN Center, is pooling the expertise of groups of the world's leading scientists in the fields of atomic and nuclear physics, antimatter research, quantum optics and metrology. Together, the scientists are endeavoring to find answers to fundamental questions of physics – such as whether natural constants really are constant. This group consists of the Max...

[ more ]

Taiwan has had its own silicon sphere since 24 November 2018. After the revision of the International System of Units (SI), it is possible to use this sphere to realize the unit of mass. The sphere – or to be more precise: the isotope-enriched 1 kg 28Si mass standard – was handed over to the Industrial Technology Research Institute of Taiwan (ITRI) by PTB President Prof. Joachim Ullrich and by the...

[ more ]
In the new International System of Units (SI), seven fundamental constants will be determined as defining reference entities. The seven base units – arranged in the outer circle of the diagram – will lose their prominent role. (Diagram: BIPM)

On the occasion of their 26th General Conference on Weights and Measures (CGPM) in November 2018 in Versailles, the signatory states of the Metre Convention decided to fundamentally reform the International System of Units (SI). This resolution stipulates that, in the future, all SI units will be based on the numerical values laid down for seven selected natural constants. In passing this...

[ more ]
a: T1 map of the heart of a healthy volunteer. b: Evaluation of the accuracy of the T1 values in a phantom for different heart rates (bpm). The accuracy of the T1 values (red) is independent of the heartbeat, whereas MOLLI – the most widely used T1 imaging method – underestimates T1 values at high heart rates (blue).

Magnetic resonance imaging (MRI) is an important imaging procedure in cardiology. To date, only qualitative imaging has been possible with MRI, since the measuring time is limited due to heart movements and breathing. A new image reconstruction procedure has now been developed at PTB. This method quantifies the biophysical parameters of the cardiac muscle with high spatial resolution and thus...

[ more ]
At an altitude of 2400 m, the spectroradiometer is facing the rising sun in Izaña.

Within the scope of a cooperation project involving PTB and the Gigahertz- Optik company, a new compact array spectroradiometer was developed, characterized and field-tested. This new device can measure the direct spectral irradiance of the Sun on Earth with very little effort and at short intervals, thus allowing conclusions to be drawn as to the total ozone column of the Earth's atmosphere.

[ more ]
Schematische Darstellung der Kombination aus FEM-Berechnung der elektrischen Feldstärkeverteilung und GIXRF-Messungen an einer Si3N4-Gitterstruktur auf einem Silizium-Substrat.

The increasing complexity of nanostructured surfaces used in technological applications makes their metrological characterization challenging. The importance of highly complex nanostructures consisting of several materials is particularly noticeable in the semiconductor industry. At PTB's laboratory at the BESSY II electron storage ring, it has now been demonstrated on a Si3N4 nanostructure on a...

[ more ]
Taking a water sample from the River Oker in Braunschweig

Mercury is toxic for many organisms. In the environment, mercury occurs everywhere and in various chemical forms. These mercury compounds are then absorbed by organisms via food, water and air. To assess the risks exhaustively, all forms of mercury as well as their possible conversion products must be known and determined. A traceable analytical method has therefore been developed to enable the...

[ more ]
Sketch of the TLD-based spectrometer. Basic principle: The deeper the radiation penetrates the spectrometer, the higher its energy.

In the laser materials processing of workpieces unwanted X-rays can occur. Their dose rate and spectral distribution have now been accurately determined for the first time.

[ more ]
One of the new designs that ensure a well-balanced relation of the stiffness: a modified cantilever with cut-outs in the beam.

Today, atomic force microscopy (AFM) is faced with the challenge of measuring 3D structures reliably. State-of-theart 3D measurements have been prone to errors since commercially available cantilevers (i.e. the measuring pins used in an AFM) do not react equally when exposed to forces from three spatial dimensions. At PTB, this problem has been successfully addressed by developing new cantilevers....

[ more ]
1: The clamping device for flat ribbon cables, which features an adjustable channel height, is pressed together by means of screwed joints and can also be stacked. 2: Round cables are fixed inside the second cable clamp by means of several spring elements.

Modern low-temperature systems increasingly make use of “dry” cryostats whose cooling effect is reached in vacuum solely by direct thermal contact. However, cables and electric wiring may impede the cooling process if they are not coupled thermally at suitable locations between room temperature and operating temperature. At PTB, two new designs have therefore been developed to thermally couple...

[ more ]
The voltage divider: The Perspex tube contains 99 high-precision resistors that can be connected either in series or in parallel.

Accurate measurements of high voltages in the range of 200 kV require the use of voltage dividers. These devices divide high voltages into smaller ones that can only then be accurately measured. The size of the signal is determined by the scale factor. Up to now, this factor had to be determined by regularly calibrating the voltage dividers against national standards. At PTB, a self-traceable...

[ more ]

Awards

Frank Härtig

Dr. Härtig, the head of Division 1 “Mechanics and Acoustics” has been appointed President Elect of IMEKO following a unanimous vote in his favor. In the coming three years, he will coordinate 24 technical committees. In 2021, he will then take over the presidency of IMEKO for three years.

Gisa Foyer , Holger Kahmann

Mr. Kahmann, who works in Department 1.2 “Solid Mechanics” and...

[ more ]

What can we expect from the revision of the International System of Units (SI), which was approved on 16 November 2018 and will enter into force on 20 May 2019? The answer depends on who you ask – an ordinary citizen, a student, a scientist or a metrologist in industry. The editorial staff of maßstäbe has asked this question – and gathered the answers in a new issue that is just as colorful and...

[ more ]

“QuantumFrontiers” is a joint project of Leibniz University Hannover and TU Braunschweig that is realized in close collaboration with PTB. This project will become an excellence cluster and will thus receive several million euros of support within the scope of the excellence strategy of the Federal Republic of Germany and of the German federal states. This excellence strategy aims to promote...

[ more ]
Prof. Dr. Joachim Ullrich (President of PTB), Prof. Dr. Gavin O’Connor with Prof. Anke Kaysser-Pyzalla (President of TU Braunschweig) and Dr. Bernd Güttler (Head of Division 3 “Chemical Physics and Explosion Protection” of PTB) (from left to right; photo: Bernt Erlewein, TU Braunschweig)

Dr. Gavin O’Connor was jointly appointed as a university professor by TU Braunschweig and the Physikalisch-Technische Bundesanstalt (PTB). He assumed this post on 1 September 2018. Dr. O'Connor is a 45-yearold chemist who specializes in mass spectrometry, especially in the field of biological measurements and chemical metrology. Prior to his appointment as a professor, Dr. O'Connor worked for the...

[ more ]

PTB News 1.2019PTB News 1.2019

Awards

Frank Härtig

Dr. Härtig, the head of Division 1 “Mechanics and Acoustics” has been appointed President Elect of IMEKO following a unanimous vote in his favor. In the coming three years, he will coordinate 24 technical committees. In 2021, he will then take over the presidency of IMEKO for three years.

Gisa Foyer , Holger Kahmann

Mr. Kahmann, who works in Department 1.2 “Solid Mechanics” and...

[ more ]
In the new International System of Units (SI), seven fundamental constants will be determined as defining reference entities. The seven base units – arranged in the outer circle of the diagram – will lose their prominent role. (Diagram: BIPM)

On the occasion of their 26th General Conference on Weights and Measures (CGPM) in November 2018 in Versailles, the signatory states of the Metre Convention decided to fundamentally reform the International System of Units (SI). This resolution stipulates that, in the future, all SI units will be based on the numerical values laid down for seven selected natural constants. In passing this...

[ more ]
At an altitude of 2400 m, the spectroradiometer is facing the rising sun in Izaña.

Within the scope of a cooperation project involving PTB and the Gigahertz- Optik company, a new compact array spectroradiometer was developed, characterized and field-tested. This new device can measure the direct spectral irradiance of the Sun on Earth with very little effort and at short intervals, thus allowing conclusions to be drawn as to the total ozone column of the Earth's atmosphere.

[ more ]
Schematische Darstellung der Kombination aus FEM-Berechnung der elektrischen Feldstärkeverteilung und GIXRF-Messungen an einer Si3N4-Gitterstruktur auf einem Silizium-Substrat.

The increasing complexity of nanostructured surfaces used in technological applications makes their metrological characterization challenging. The importance of highly complex nanostructures consisting of several materials is particularly noticeable in the semiconductor industry. At PTB's laboratory at the BESSY II electron storage ring, it has now been demonstrated on a Si3N4 nanostructure on a...

[ more ]
Taking a water sample from the River Oker in Braunschweig

Mercury is toxic for many organisms. In the environment, mercury occurs everywhere and in various chemical forms. These mercury compounds are then absorbed by organisms via food, water and air. To assess the risks exhaustively, all forms of mercury as well as their possible conversion products must be known and determined. A traceable analytical method has therefore been developed to enable the...

[ more ]
Sketch of the TLD-based spectrometer. Basic principle: The deeper the radiation penetrates the spectrometer, the higher its energy.

In the laser materials processing of workpieces unwanted X-rays can occur. Their dose rate and spectral distribution have now been accurately determined for the first time.

[ more ]
One of the new designs that ensure a well-balanced relation of the stiffness: a modified cantilever with cut-outs in the beam.

Today, atomic force microscopy (AFM) is faced with the challenge of measuring 3D structures reliably. State-of-theart 3D measurements have been prone to errors since commercially available cantilevers (i.e. the measuring pins used in an AFM) do not react equally when exposed to forces from three spatial dimensions. At PTB, this problem has been successfully addressed by developing new cantilevers....

[ more ]
1: The clamping device for flat ribbon cables, which features an adjustable channel height, is pressed together by means of screwed joints and can also be stacked. 2: Round cables are fixed inside the second cable clamp by means of several spring elements.

Modern low-temperature systems increasingly make use of “dry” cryostats whose cooling effect is reached in vacuum solely by direct thermal contact. However, cables and electric wiring may impede the cooling process if they are not coupled thermally at suitable locations between room temperature and operating temperature. At PTB, two new designs have therefore been developed to thermally couple...

[ more ]
The voltage divider: The Perspex tube contains 99 high-precision resistors that can be connected either in series or in parallel.

Accurate measurements of high voltages in the range of 200 kV require the use of voltage dividers. These devices divide high voltages into smaller ones that can only then be accurately measured. The size of the signal is determined by the scale factor. Up to now, this factor had to be determined by regularly calibrating the voltage dividers against national standards. At PTB, a self-traceable...

[ more ]

What can we expect from the revision of the International System of Units (SI), which was approved on 16 November 2018 and will enter into force on 20 May 2019? The answer depends on who you ask – an ordinary citizen, a student, a scientist or a metrologist in industry. The editorial staff of maßstäbe has asked this question – and gathered the answers in a new issue that is just as colorful and...

[ more ]

“QuantumFrontiers” is a joint project of Leibniz University Hannover and TU Braunschweig that is realized in close collaboration with PTB. This project will become an excellence cluster and will thus receive several million euros of support within the scope of the excellence strategy of the Federal Republic of Germany and of the German federal states. This excellence strategy aims to promote...

[ more ]
Prof. Dr. Joachim Ullrich (President of PTB), Prof. Dr. Gavin O’Connor with Prof. Anke Kaysser-Pyzalla (President of TU Braunschweig) and Dr. Bernd Güttler (Head of Division 3 “Chemical Physics and Explosion Protection” of PTB) (from left to right; photo: Bernt Erlewein, TU Braunschweig)

Dr. Gavin O’Connor was jointly appointed as a university professor by TU Braunschweig and the Physikalisch-Technische Bundesanstalt (PTB). He assumed this post on 1 September 2018. Dr. O'Connor is a 45-yearold chemist who specializes in mass spectrometry, especially in the field of biological measurements and chemical metrology. Prior to his appointment as a professor, Dr. O'Connor worked for the...

[ more ]
a: T1 map of the heart of a healthy volunteer. b: Evaluation of the accuracy of the T1 values in a phantom for different heart rates (bpm). The accuracy of the T1 values (red) is independent of the heartbeat, whereas MOLLI – the most widely used T1 imaging method – underestimates T1 values at high heart rates (blue).

Magnetic resonance imaging (MRI) is an important imaging procedure in cardiology. To date, only qualitative imaging has been possible with MRI, since the measuring time is limited due to heart movements and breathing. A new image reconstruction procedure has now been developed at PTB. This method quantifies the biophysical parameters of the cardiac muscle with high spatial resolution and thus...

[ more ]

PTB-News 3.2018

Optical clock in its transport container and optical components for frequency transmission at the LSM underground laboratory.

The passage of time depends on the position of the observer in a gravitational potential. For a large mass such as the Earth’s, this effect can be measured by means of high-precision atomic clocks and used to determine the difference in height between two clocks. For the first time, PTB’s portable strontium optical clock has allowed flexibility in the selection of the place where one of the clocks...

[ more ]
Scanning electron microscopic image of a typical GaN pillar after a nanoindentation measurement with a Berkovich indenter

Pillar-like nanoobjects can now be characterized mechanically using the indentation technique. This has been made possible by a novel evaluation method developed at PTB and by a correction procedure for the compressibility of the columns.

[ more ]
Representation of the double ionization chamber for the measurement of atomic photoionization cross sections with synchrotron radiation at the Metrology Light Source (MLS)

In collaboration with Fraunhofer IPM in Freiburg/Breisgau, interaction cross sections for the photoionization of noble gases in the VUV spectral range have been measured at PTB’s Metrology Light Source (MLS). The results have allowed the existing datasets to be extended, and have smaller uncertainties and reliable metrological traceability to the International System of Units (SI). They can be...

[ more ]
PTB’s measurement setup for the electrochemical measurement of the pHT value. The system contains Harned cells filled with artificial sea water samples whose voltages are measured under temperature-controlled conditions.

In cooperation with the Leibniz Institute for Baltic Sea Research Warnemünde, pH values of average-salinity sea water (5 to 20 g/kg sea water) have been measured at PTB for the first time in such a way that they can be traced to PTB’s primary pH standard. This ensures comparability of pH values measured in the sea, which is indispensable for applications such as the reliable quantification of sea...

[ more ]
Processed and conditioned biogas is an important part of the German Federal Government’s energy concept in pursuit of low-carbon energy generation. (Photo credit: Ökobit GmbH)

Extensive uncertainty analyses and innovative methods for uncertainty determination allow state reconstruction systems to be used for commercial transactions in the gas grids of regional utility companies in order to determine the energy content of natural gas. PTB has provided the preconditions for the use of these systems.

[ more ]
Measurement setup during a measurement with the vibrometer. The vibrometer is located in the blue housing. The foil is placed in the red lens tube and lies on the water surface.

A novel measurement setup has been developed at PTB for the primary calibration of ultrasonic hydrophones. Hydrophones are sensors used to determine ultrasonic pressure wave in liquid media. They are mainly used in medical engineering in order to test ultrasonic equipment. The new facility covers a larger frequency range and simultaneously exhibits lower uncertainty.

[ more ]
Schematics of the measurement setup for the calibration of the inductive voltage divider (in the figure: ”divider”) with the two JAWS voltage standard systems. The lock-in voltage amplifier together with the transformer (centre of the picture) amplifies the signal and, thus, increases the sensitivity of the measurement method.

PTB is developing a measuring system based on pulse-driven Josephson voltage standards. This system is designed to allow alternating voltages to be measured with great accuracy at frequencies of up to 100 kHz and voltages of more than 100 V. Since the output voltages of Josephson voltage standards are limited to a few volts, it is necessary to use voltage dividers. An inductive voltage divider has...

[ more ]
Geometrische Abweichungen bei der Kegelstrahlgeometrie. Die Bilder entstehen in unterschiedlichen Tiefen in der Szintillatorschicht des Detektors. In Rot ist der Strahlengang ohne Filter und umgebendes Material zu sehen in Blau mit Filter und umgebendem Material. Der Effekt ist abhängig vom Röntgenspektrum in Kombination mit Probenmaterial und Abstand a.

Until recently, length measurements performed by means of industrial X-ray computed tomography (CT) based on cone beam geometry (without additional tactile reference measurements) exhibited relative measurement uncertainties of approx. 1 · 10-4. A procedure developed at PTB allows this uncertainty to be improved by a factor of at least 10. This new development relies on a pixel-resolved distance...

[ more ]
Beispielhafter Strahlenverlauf: oben mit vier Reflexionen pro Spiegel, darunter in der neuen Herriott-Zelle mit dreifach erhöhter Anzahl an Reflektionen (12 Reflexionspunkte pro Spiegel)

Tiny amounts of certain gases can have considerable effects on human health, the environment and industrial processes. It is now possible to detect such gas quantities with enhanced sensitivity resolution by means of a Herriott cell developed at PTB. Plane mirrors inside the cell make it more effective, allowing the optical path length to be increased by more than one order of magnitude at an...

[ more ]

Bidirectional amplifiers are necessary for the transmission of ultra-stable optical frequencies over long-distance optical fiber links in order to compensate for the optical loss of approximately 20 dB per 100 kilometers. Brillouin fiber amplifiers developed at PTB support such bidirectional operation with a gain of up to 45 dB and have been successfully installed in the international optical...

[ more ]

Awards

 

Joachim Ullrich

PTB-Präsident Prof. Dr. J. UllrichThe president of PTB has been awarded an honorary science doctorate by Leibniz University Hannover. By awarding this honorary title, the university has recognized Professor Ullrich’s outstanding accomplishments in the field of experimental quantum physics. These accomplishments include more than 450 publications in renowned specialist journals and numerous research prizes,...

[ more ]
Weltweit einmaliges Forschungszentrum mit PTB-Beteiligung (Foto: Carpus + Partner)

The new building housing the Hannover Institute of Technology (HITec) at Leibniz University Hannover was inaugurated on 6 July. This institute is the first in Europe to unite basic and applied research and technology development on quantum physics and geodesy under one roof. The main partner organizations directly involved in HITec’s research program are: the Laser Zentrum Hannover e.V. (LZH), the...

[ more ]

A new association, the German National Committee of CIE (Deutsches Nationales Komitee der Internationalen Beleuchtungskommission CIE – DNK-CIE) was founded at PTB on 5 April 2018. Dr. Armin Sperling was elected as the first chairperson of the new association.

[ more ]

A collaborative research centre (CRC) on diagnostic radiology called “Matrix in Vision” has been created at the Charité university hospital in Berlin (contact: Prof. Dr. Bernd Hamm). The Freie Universität Berlin, the Max Planck Institute of Colloids and Interfaces, the BAM Federal Institute for Materials Research and Testing and PTB are also involved in this CRC in addition to Charité. This...

[ more ]
Titelseite Broschüre Junge Wissenschaft

PTB is now home to a new publication, Junge Wissenschaft, an online journal (Opens external link in new windowhttps://www.jungewissenschaft.ptb.de). Young scientists (no older than 23 years old) can publish their findings in accordance with the usual rules applying to scientific publications – including a peer review process. Junge Wissenschaft is published, edited, and editorially supported by PTB’s Press and Information Office....

[ more ]

PTB News 2.2018PTB News 2.2018

PTB scientist Johannes Thielking with the laser setup for measurementsof the thorium-229 nuclear properties

The nucleus of thorium-229 possesses a property that is unique among all known nuclides: It should be possible to excite it with ultraviolet light. To date, little has been known about the low-energy state of the Th-229 nucleus that is responsible for this property. Now it has become possible for the first time to determine the charge distribution of this nuclear state by means of spectroscopic...

[ more ]
Comparison of measured and modeled resonant frequencies of the forcetransducer investigated as a case study for dynamic calibrations with differentload masses. The diagram shows the modeled resonant frequenciesand the resonant frequencies determined experimentally with shock andsine excitation as a function of the load mass. The measurement point for1 kg represents a typical sinusoidal calibration with large masses and excitationsup to a few kHz. In addition, the resonances determined experimentallyat shock excitations are also plotted.

Good agreement between the results of different calibration methods (shock or sine) has been achieved for the first time. This was made possible by a mathematical model of a measuring setup with the force transducers elastically coupled on both sides.

[ more ]

Conventional calibration certificates could soon become history. To furnish proof that a measuring instrument has been calibrated and of how this has been done, metrology institutes throughout the world could, in the near future, use digital calibration certificates (DCCs) rather than their analog version. Especially the fact that they are machine-readable speaks in favour of DCCs for production...

[ more ]

The more power that is generated by regenerative energy sources, the more complex the power grids become. This makes it ever more important to set up intelligent power grids where producers, consumers and measurement points communicate with each other. Within the scope of an EU project, mathematical modeling procedures have been developed to make the behavior of power grids more predictable and to...

[ more ]
Fluorescence camera system with camera head, electronic plug-in unit in the PC and control software showing a tissue section with fluorescent sentinel lymph nodes (highlighted in red). Detail screen bottom left: Arrangement of the LEDs in the camera head.

PTB has developed a camera system for sentinel lymph node mapping using the fluorescent contrast agent indocyanine green. The system has been successfully tested in collaboration with the Department of Gynecology of the Charité university hospital in Berlin.

[ more ]
A topological insulator insulates in the bulk but is conductive at the surface. Ferromagnetic doping also makes the surface perpendicular to the direction of magnetization M insulating. One-dimensional “edge channels”, i.e. electric ring currents, run at the edge of the film. In this state, the Hall resistance ρxy is quantized at zero magnetic field and takes the value of the von Klitzing constant h/e2, while at the same time, the longitudinal conductivity ρxx becomes zero.

In collaboration with the University of Würzburg, PTB has succeeded in measuring the quantum anomalous Hall effect with a relative measurement uncertainty of 2.5 · 10–7. This represents an improvement by nearly three orders of magnitude. It brings the on-chip integration of quantum Hall resistance standards with Josephson voltage standards one step closer to reality, which would be a breakthrough...

[ more ]

According to a European quality guideline, elemental contaminations in medicinal products have to be adequately controlled. Consequently, the “European Directorate for the Quality of Medicines and HealthCare” (EDQM), the Joint Research Center (JRC) Geel, the Federal Institute for Materials Research and Testing (BAM) and the PTB have prepared high-accuracy reference solutions for four particularly...

[ more ]
Two pistons generate a constant volume rate by alternately pushing the fluid out of the respective cylinder.

Flow rate measuring technology requires exact fluid delivery for testing and calibration rigs. These systems should be able to continuously deliver constant volume flow rates. PTB has developed a new device consisting of two synchronized piston systems which can generate a constant and pulsation-free fluid flow. In addition, the flow rate can be varied quickly. Optical positioning provides exact...

[ more ]
Flange with support to accommodate force sensors. Background: typical nacelle test stand. PTB's new force lever system can be mounted here.

The traceable measurement of torques of more than 2 MN ∙ m is of paramount importance in areas such as wind energy. An invention developed at PTB enables traceability by segmenting the torque into several force signals that are measured over a defined lever length. In addition, the torque sensor can decouple most of the mechanical disturbing components. The measurement uncertainty amounts to a...

[ more ]
Segmented gripper jaw with markers (red) to measure the gripping force

The handling and exact controlling of microgrippers requires high precision. The measuring devices used to date are characterized by great manufacturing effort and only allow a limited selection of materials to be used. PTB's concept simplifies the measurement of the gripping force: the grippers are segmented and interconnected by means of spring elements to reduce their stiffness. Markers are...

[ more ]

Awards

Dietmar Drung, Hansjörg Scherer, Martin Götz, Eckart Pesel
These staff members of departments 7.2, Cryophysics and Spectrometry, (D. Drung) and 2.6, Electrical Quantum Metrology, (H. Scherer, M. Götz, E. Pesel) have won this year's Helmholtz Prize in the category “Precision measurements in applied metrology”. They have been given this award for the development of a new current amplifier, the...

[ more ]

Der PTB-Jahresbericht hat mit der gerade erschienenen Ausgabe 2017 ein neues Gesicht bekommen: knapper, nachrichtlicher, bunter, informativer. Sie finden ihn als pdf zum Herunterladen auf der Website der PTB unter „Presse & Aktuelles“ und dort unter „Zeitschriften & Magazine“.

Wenn Sie ihn als gedruckte Version kostenlos erhalten möchten, schicken Sie bitte eine Bestellung per E-Mail an Opens window for sending emailpresse@p...

[ more ]

This year's World Metrology Day (on 20 May) marks the start of the countdown to the introduction of the new International System of Units (SI). The new – or rather revised – SI, in which all units are traced to fundamental constants, will in all likelihood be adopted by the CGPM in November 2018. The revised SI will then officially come into force on next year's World Metrology Day (20 May 2019)....

[ more ]

PTB News 1.2018PTB News 1.2018

SEM image of a lithographic test structure: the periodical lines of the measuring field with dimensions of 4 μm × 4 μm (top right) are rotated by 10° with reference to the symmetry axis of the surrounding irregular nanostructures to be able to spatially separate the respective X-ray signals from each other.

Photolithography is used in industry to manufacture semiconductor elements. Hereby, the nanostructures of the logic gates of a photomask are imaged optically on the semiconductor wafer. For process control, measuring fields consisting of nanostructures in a periodical arrangement are distributed at different points over the entire photomask. The space and funds available being limited, these...

[ more ]
Principle of absolute, time-resolved temperature measurement The optically induced increase in temperature is read out with subnanosecond time resolution by means of a magnetic tunnel junction which is located inside a nanostructure.

PTB has developed a method that can be used to manage the temperature of nanocircuits. The method is based on magnetic tunnel junctions and enables quantitative temperature measurements with a time resolution smaller than a nanosecond. Hereby, the tunnel junction acts as a calibrated thermometer by exploiting the temperature dependence of the tunnel resistance. The principle has been demonstrated...

[ more ]
Figure: a) Reconstructions of varying nanoparticle quantities, each measured with a conventional transmitreceive coil system (top) and with the receive-only coil (bottom). The red dots represent the sample positions. b) Product layout of an optimized 1D receive-only coil

In cooperation with industrial partners, PTB has developed a pick-up coil for a novel imaging method called magnetic particle imaging (MPI). This coil has already been successfully implemented and tested at the MPI system in Berlin. The new coil considerably improves the sensitivity of the technique. Quantities of magnetic nanoparticles as small as a few nanograms can now be detected.

[ more ]
In certain magnetic field ranges, fractional (blue curve) and integer QHE lead to resistance values that are only given by the fundamental constants h and e, and by a rational number. The ratio of 1 : 6, which had been predicted theoretically for the two resistance values characterized by the two arrows, has been experimentally confirmed for the first time with a measurement uncertainty of a few parts in 108. The inserted image is a schematic representation of the composite fermion in this fractional QHE regime. The quasi-particle consists of an electron to which two magnetic flux quanta are bound; it carries the charge e/3.

The “new SI”, scheduled for May 2019, is based on fundamental constants which can be directly measured by means of macroscopic quantum effects. Verifying the theoretical fundaments of these effects experimentally with the greatest accuracy is one of the core tasks of metrology. In the case of the quantum Hall effect, this has now been successfully done for the first time for a state in which the...

[ more ]
Image of the atoms in the ionic crystal when the interaction inside a chain is higher (a) or smaller (b) than between the two chains. A phase transition occurs between the two regimes; this phase transition leads to a break in the symmetry in finite systems (see red and yellow configurations). The graph below represents the measured curve of the order parameter Ф (a measure of the symmetry in the system). α is an experimental parameter which determines the distance between the two chains.

Investigations carried out at PTB’s QUEST Institute in a model system consisting of ion chains sliding over each other have provided fundamental findings on friction in nanostructures and biomolecules. In the event of defects in the lattice structure, a transition toward superlubricity has been observed and explained.

[ more ]
The prototype of the ultrasound level meter consists of a notebook, an analog-to-digital converter, a power module, a preamplifier and a 1/4-inch condenser microphone cartridge.

In cooperation with the Institut für Arbeitsschutz
(IFA) of the Deutsche Gesetzliche
Unfallversicherung (DGUV),
the prototype of a portable measuring
system for airborne ultrasound has
been developed at PTB. It will allow the
determination and assessment of potential
workplace risks represented by
widespread ultrasonic machines which
can generate very high sound pressure
levels.

[ more ]
The figure shows rotationally symmetric grooves with a continuous color gradient on a wafer.

For the exact processing of silicon wafers, it is necessary to identify the orientation of the crystal within the silicon wafer. An invention by PTB has improved the determination of the crystal orientation in <110>-wafers by additionally detecting incident light on special structures (see figure). These test structures are positioned on the surface and have enabled an automated determination...

[ more ]
Die Mischvorrichtung (rot) umgibt einen zentralen Strömungskanal und leitet ein Verdünnungsgas zur optimierten Vermischung hinein.

To date, two types of particulate matter or of fluid media (as encountered in exhaust gas measuring techniques) have been mixed by feeding one of the media laterally to the flowing direction of the other medium. These two media only mix homogeneously far way from the feeding point. A mixing module developed at PTB reduces the length of the section required for this process to take place, which can...

[ more ]
Example of a calibration standard of PTB in a star circuit

Network analyzers with more than two ports must be calibrated daily for use in electronics, communication engineering and high-frequency technology. This calibration can currently be very time consuming. A new calibration method from PTB mitigates this situation. Here, novel multiport star circuit standards are characterized using a PTB reference calibration (see figure). The network analyzer is...

[ more ]

The International System of Units (SI) is being fundamentally revised. The foremost expert committee in the world of metrology, the International Committee for Weights and Measures (Comité international des poids et mesures, CIPM), issued its fundamental recommendation for this development at its recently concluded annual assembly. It is hoped that, at their general conference in November 2018,...

[ more ]

Awards

 

Roman Schwartz

 On 11 October 2017, PTB's Vice President was elected President of the International Committee of Legal Metrology (CIML) for a term of office of 6 years. He had previously already been CIML Vice President for a long time.

Uwe Arz

 This staff member of Department 2.2, High Frequency and Electromagnetic Fields, has received the Best Oral Presentation Award of the 90th ARFTG...

[ more ]

Topping-out ceremony for an extension to PTB’s Willy Wien Laboratory: The new building will provide laboratory and office space and will be directly connected to the neighboring electron-storage ring Metrology Light Source (MLS). With a gross floor area of approx. 1400 square meters, it will accommodate office, laboratory and seminar space as well as utility rooms. This extension has been...

[ more ]

First groundbreaking for a highly specialized research building: the new Walther Meißner building will provide laboratory space as well as measuring and clean rooms to measure temperature with the greatest possible accuracy and for research activities relating to all aspects of superconductor sensors. The new building was designed by architects from Rohdecan in Dresden who came out as the winners...

[ more ]

Representatives from 16 European institutions operating synchrotron radiation sources and/or free-electron lasers met in Brussels for the LEAPS (League of European Accelerator-based Photon Sources) consortium on 13 November 2017. This concentrated load of scientific excellence is to help take up challenges in the fields of energy, transportation, health, food safety and environmental protection....

[ more ]

This year again, students are invited to take part in topical projects of PTB under the slogan “Dein genauester Sommer!” (Your most accurate summer) from 1 August until 28 September 2018. You are welcome to submit your application for the voluntary internship taking place within the scope of MetroSommer if you study a STEM subject at a German university between the third semester of a Bachelor’s...

[ more ]

PTB-News 3.2017PTB-News 3.2017

Schema des Raster-Scan-Verfahrens, das am HIT verwendet wird. Der Ionenstrahl (grün) wird mithilfe von Magneten über ein vordefiniertes Raster gescannt, wobei an jeder Position die erforderliche Zahl der Teilchen bestimmt wird. Durch Variation der Energie wird zusätzlich die Eindringtiefe der Ionen in den Tumor (das Gebilde auf der rechten Seite des Bildes) variiert. So kann der Tumor insgesamt sehr exakt bestrahlt werden. (Abb.: HIT)

Tumor irradiation by carbon ions is clearly becoming more precise. With the help of investigations carried out by the Physikalisch-Technische Bundesanstalt (PTB), the accuracy of the absorbed dose measurement could be improved by a factor of three. The German Cancer Research Center (DKFZ) and the Heidelberg Ion Beam Therapy Center (HIT) were also involved in this research collaboration.

[ more ]
Prototyp des neuen SQUID-18-Kanal-Moduls. (a) Multikanalmodul. (b) Messsystem mit sieben Multikanalmodulen.

In order to develop the highly sensitive magnetic measurement technology for biomedical research further and to deal with fundamental questions of physics, a new multichannel vector magnetometer module has been developed at PTB. This 18-channel device forms the basis of a measuring system using a modular design.

[ more ]
Verification of the 3D-Lasermeter during measurements at the Polish metrology institute (GUM). A constant distance of 19 m was measured with the wavelengths 532 nm and 1064 nm of the 3D-Lasermeter manufactured by SIOS GmbH (small picture). When using a network of temperature sensors to compensate for the refractive index, the distance is allegedly reduced by up to 30 μm (red curve) during the warm-up phase. Contrary to this, the distance from the intrinsically determined correction of the refractive index (blue curve) remains stable (apart from the slightly higher noise).

Within the scope of an international project, PTB has developed the prototype of a 3D-capable interferometer that compensates for the optical refractive index of air intrinsically. This so-called 3D-Lasermeter has been successfully tested in two series of tests under difficult industrial ambient conditions.

[ more ]
Chip mit supraleitender SQUID-Serienschaltung des Wanderwellenverstärkers im Probenhalter mit Mikrowellenanschlüssen. Die Serienschaltung enthält 2296 SQUIDS in einer 11,5 cm langen mäanderförmigen Hochfrequenzleitung.

Quantum information technology requires low-noise and extreme broadband amplifiers for weak microwave signals. A novel parametric amplifier with Josephson junctions that was developed at PTB distinguishes itself through high gain, broad bandwidth and low noise.

[ more ]
Geometrical phantom (framed in blue) for the assessment of the level of detail, and magnetic test pieces of different dimensions (framed in white) with defined combinations of nanoparticles and resins from generative manufacturing. Size of the assembly space: 230 mm × 160 mm × 125 mm.

A procedure further developed by PTB allows plastic test pieces (phantoms) containing well-defined additions of magnetic nanoparticles to be manufactured for the first time. This procedure opens up the possibility of making nanoparticle distributions that are precise and have long-term stability available to biomedicine in any arbitrary geometries for the testing of magnetic imaging modalities.

[ more ]
Referenzmessplatz für den Gesundheitszustand von Li-Ionen-Batteriezellen für E-Fahrzeuge. Aufgrund der großen elektrochemisch gespeicherten Energiemenge müssen die Alterung und die Impedanzmessungen in klimatisierten Sicherheitsschränken durchgeführt werden.

For the practical use of battery-operated electric vehicles, measurement methods are required which provide fast and reliable information as to whether and to what extent the maximum charging capacity of a Li ion battery has already decreased. This is referred to as the “state of health”. To measure a battery's state of health, PTB has installed a reference measuring set-up that uses...

[ more ]
Das EUI-Instrument von Solar Orbiter während der Montage im großen Vakuumtank an der MLS

Solar Orbiter is a spacecraft of the European Space Agency (ESA) which is intended to orbit and investigate the Sun scientifically for seven years. This mission is currently scheduled to start in October 2018. Three of the Solar Orbiter’s instruments will measure the Sun in the vacuum UV or extreme ultraviolet radiation spectral range with radiation at wavelengths shorter than 130 nm. The...

[ more ]
Anordnung der Sensorelemente in der Gassensorik.

A new miniature gas sensor developed by PTB not only precisely determines the volumetric flow of a gas but also identifies the composition, for example, of several energy gases.

[ more ]
Streifenelektrode

Surface resistance is considered an important parameter in explosion protection to assess the electrostatic charge of building elements which might lead to electrostatic discharge and, in the worst case, to an ignition of an explosive atmosphere.

[ more ]
Mikrofluidische Baugruppe mit Flusskanal (Mitte) und Sensorelektroden.

The quantitative investigation of cells in blood by means of flow cytometry is a routine procedure in medical diagnostics. Thanks to the development of this novel procedure by PTB, it has become possible to determine the concentrations of erythrocytes, thrombocytes and leukocytes in blood samples simultaneously and reliably by means of AC impedance.

[ more ]

Awards

PTB
The German Council of Science and Humanities has evaluated PTB and awarded it an excellent rating. The results go above and beyond the previous outstanding rating from the first evaluation in 2008. In the report which was published on 2 May, the Council praised PTB's performance of legal core tasks, research activities and services as well as strategy and planning processes that are necessary...

[ more ]

As the first of three pilot projects within the national initiative “Quantum technology – basics and applications” (QUTEGA), which was created by the Federal Ministry of Education and Research, the joint project “Optical single ion clocks for users” (optIclock) was started on 1 May. Under the special guidance of TOPTICA Photonics AG and PTB, it is intended to realize a demonstrator for optical...

[ more ]

Mit dem Helmholtz- Preis ehren der Helmholtz- Fonds e. V. und der Stifterverband für die Deutsche Wissenschaft alle zwei bis drei Jahre Wissenschaftler für Präzisionsmessungen in Physik, Chemie und Medizin.

[ more ]

PTB News 2.2017PTB News 2.2017

euspen

Die European Society for Precision Engineering and Nanotechnology (euspen) veranstaltet einmal im Jahr an wechselnden Orten in Europa eine internationale Fachkonferenz mit Industrieausstellung, die als Forum für den Austausch über Innovationen, Forschung und Entwicklungen im Bereich der Präzisionsmess- und Fertigungstechnik dient. In diesem Jahr findet die Konferenz vom 29.5 bis 2.6 in...

[ more ]
PTB scientist Christof Gaiser with the core of the dielectric-constant gasthermometer. The different silver-colored pressure vessels have specialcapacitors which are filled with helium to carry out the measurement thattakes place inside them.

PTB has succeeded in measuring the Boltzmann constant k independently. A fundamental condition laid down by the Consultative Committee for Thermometry (CCT) has thereby been met, so that all obstacles to the redefinition of the kelvin have been removed by fixing the value of the Boltzmann constant. The final measurements of k with a dielectric-constant gas thermometer were conducted with a...

[ more ]

In the case of blood samples with pathologically modified blood cells, the hemolysis and staining methods used in routine diagnostics can lead to the wrong identification of certain cell populations or to an inaccurate determination of their concentration. In contrast to this, an AC impedance procedure, which was developed at PTB, allows whole blood samples to be analyzed without disturbing...

[ more ]

Since the beginning of this year, the DFG has been promoting the establishment and operation of the Core Facility “Metrology of Ultra-Low Magnetic Fields” at PTB. In this way, PTB grants external scientists from universities, international metrology institutes and companies access to its know-how and its equipment for the measurement of extremely small magnetic fields which is unique worldwide.

[ more ]
TES/SQUID detector module (interior view of the cryostat without the radiation shields)

For many years, PTB has been leading in the development of current sensors on the basis of SQUIDs (Superconducting QUantum Interference Devices). Now, PTB's SQUID current sensors are used successfully as essential components of superconducting microcalorimeters to characterize novel single-photon emitters and microlasers for quantum optics.

[ more ]

PTB has topped its own world record established a year ago where electric currents were generated with singleelectron pumps and their quantization was verified with the greatest accuracy by means of a special measuring amplifier. The new record (which was made possible by improving the experimental setup) is a relative measurement uncertainty of only 0.16 μA/A. Moreover, this result was achieved...

[ more ]

Within the scope of a BMBF project, high-speed measurements with piezoresistive microprobes were investigated. Hereby, scanning speeds of up to 15 mm/s were successfully tested. An essential aspect of the investigations was the wear of the tip.

[ more ]

To measure medium-sized forces (of approx. 10 kN) up to very high forces (higher than 10 MN), several calibrated force transducers can be connected to obtain a build-up measuring system. Due to increasing requirements, especially in the field of very large force transducers up to 50 MN, reducing the measurement uncertainty of these systems is gaining more and more importance. Due to its special...

[ more ]

At PTB, a manufacturing procedure for monolayer graphene has been developed to produce a quantum standard for the electric unit of resistance. Thanks to its reliability and simplicity, this enhanced multi-step sublimation method allows the production of large-scale graphene structures. This also paves the way for the mass production of qualitatively highend monolayer graphene films. The produced...

[ more ]

Ultrasound is used as a therapeutic modality in medicine for various applications including the removal of kidney stones or tumors. A new procedure developed by PTB now allows a traceable spatial calibration of, e.g., high-intensity therapeutic ultrasonic equipment. Based on thermochromic foils which change color in the event of heating induced by ultrasound, it is possible to determine...

[ more ]

Awards

Jan Wernecke was awarded the 2016 Ernst Eckhard Koch Prize of the Freundeskreis Helmholtz-Zentrum Berlin at the Technische Universität Berlin for his doctoral thesis entitled “When size does matter: Dimensional metrology of nanostructured layers and surfaces using Xrays”. This paper was developed in the X-ray Radiometry Working Group at the BESSY II electron storage ring in Berlin.

[ more ]

Within the scope of the Collaborative Research Centre “Designed Quantum States of Matter” (DQ-Mat), with approx. 10 million euros of funding provided by the DFG, researchers from Leibniz University Hannover, from the Center of Applied Space Technology and Microgravity (ZARM) in Bremen and from PTB in Braunschweig have been collaborating to exploit special quantum-mechanical properties of...

[ more ]

PTB's Department 8.5, “Metrological Information Technology”, has been accepted as a member of the faculty of the Helmholtz Research School on Security Technologies (HRSST). This is a joint program of the Technische Universität Berlin and the German Aerospace Center (DLR) which was initiated in 2010 and supports, among others, excellent doctoral candidates who deal with research on a secure and...

[ more ]

The International System of Units (SI) is being fundamentally reformed. In the fall of 2018, a large international conference is going to set the historical course for the future of the SI. The new SI will be based on fundamental constants instead of the seven base units as previously. PTB has accompanied this process by means of various large-scale research projects – among others the Avogadro...

[ more ]

PTB News 1.2017PTB News 1.2017

UHV instrumentation for combined X-ray fluorescence and photoelectron spectroscopy on surfaces of silicon spheres

In order to become independent of the international prototype of the kilogram kept in Paris, the definition of the SI unit of mass, the kilogram, has to be revised. For this purpose, the number of silicon atoms in a monocrystalline silicon sphere has been determined at PTB within the scope of the Avogadro proj´ect. It is therefore necessary to measure the surface properties with the highest...

[ more ]
Reference cantilever made of silicon for determining the probing force of contact stylus instruments. The contact force is determined from the bending of the beam at the end mark (see arrow) under the influence of the contact force.

In microsystems, metallic components are increasingly being replaced by those from low-cost polymers. For the thick-ness measurement of polymers, a DIN standard, DIN 32567, is now available which was developed, among others, by PTB experts. The standard describes both optical and tactile surface measuring methods for the precise measurement of the thickness of polymer layers. The tactile methods...

[ more ]
In vivo MR spectrum with fitted result from an anatomically shaped voxel excited by means of the SHAVE method which only contains white cerebral matter (i.e. is not contaminated by gray matter). The individual peak positions in the spectrum represent metabolites, their amplitudes represent their concentrations. In the right corner of the diagram, the voxel can be seen in the brain image (yellow).

Magnetic resonance spectroscopy (MRS) allows the non-invasive deter-mination of metabolites in the human brain in vivo. However, it is usually limited to rectangular volumes. This makes it difficult to quantify the metabolites selectively in a certain cerebral structure in order to establish a precise neurochemical profile of this structure. A new pulse sequence combined with a multichannel...

[ more ]
The multispectral line scan camera decomposes the color spectrum.(Photo: Chromasens GmbH)

Today, spectral color measurements are indispensable in numerous areas of science and industry. In the printing industry, for example, clear color definitions and exact color repetitions are necessary. The procedures used to date, however, only provide random and locally limited results – and some require a large amount of time and effort. Within the scope of a joint project with the Chromasens...

[ more ]
Spatial Angle Autocollimator Calibrator: granite base plate (1), reference autocollimators (2; 3), autocollimator to be calibrated (4), linear sliding carriage (5), reflector cube (6), two-axis tilting system (7)

At PTB, a novel calibration system for autocollimators has been set up, the Spatial Angle Autocollimator Calibrator. The calibration capabilities for optical angle measurements have thus been extended from plane to spatial angles for the first time. In addition, the system allows calibrations at distances from 250 mm to 1800 mm.

[ more ]
PTB's EUV beamline at the Metrology Light Source. In the foreground (right), one can see the clean-room in which the samples are assembled. The large-scale EUV reflectometer is located at the back of it (concealed). The mirrors, some of which are very large and heavy, are mounted into the reflectometer by a robot (seen on the left in the cleanroom).

The cooperation project with Carl Zeiss SMT GmbH in the field of radiometry, which started back in 1998, has been prolonged until the end of 2020. At PTB, this cooperation project represents the starting point and the basis of a field of work which provides extensive metrological support to the German and the European semiconductor industry for the development of EUV lithography. Besides EUV...

[ more ]
Mono-atomic steps in an amphitheater structure on (111)-silicon

At PTB, a novel manufacturing procedure based on (111)-silicon wafers al-lows areas with dimensions of up to 150  µm² to be generated which exhibit both atomically smooth surfaces and surfaces with monoatomic steps. In this procedure, a self-organizing process is triggered by using a targeted heating process under ultra-high vacuum within several lithographically structured patterns. The...

[ more ]
Here, disturbing resonance frequen-cies in the staircase were significantly reduced thanks to the new Helmholtz resonator.

Whether you are a high-end music connoisseur in your living room or a record-ing engineer in your recording studio, you both know them well – the location-dependent low-resonance frequencies which can be extremely unpleasant when listening to music. Low-frequency noise originating from machines can be similarly amplified in industrial locations due to room resonances. With PTB's invention – a...

[ more ]
Diagrammatic sketch of the test mass (red) in the measuring ar-rangement

In conventional superconducting gravimeters, a test mass is levitated by the magnetic field of a superconducting coil. An elaborate adjustment allows the gravity of the earth to be measured at geographical locations by means of this measurement principle. PTB's new invention is based on an alternative geometry of the magnetic field and thus contains a new test mass in the form of a double cone. In...

[ more ]

Awards

Roman SchwartzRoman Schwartz,
Vice-President of PTB, was confirmed in his office as the “CIML First Vice-President” (CIML: International Committee of Legal Metrology) and reelected for another six years at the 51st CIML session in Strasbourg.

Raya Roshana GallasRaya Roshana Gallas
This staff member of Department 6.2, “Dosimetry for Radiation Therapy and X-ray Diagnostic Radiology”, was awarded the Otto Haxel Prize of Heidelberg...

[ more ]

As part of the Federal Government's “Nanotechnologies Action Plan 2020”, the federal authorities responsible for human and environmental safety have extended their joint research strategy.

[ more ]

The scientific exchange between PTB and its Argentinian partner institute, Instituto Nacional de Tecnologia Industriel (INTI), is growing closer.

[ more ]

This year again, students are invited to take part in topical projects of PTB under the slogan “Dein genauester Sommer” (Your most accurate summer) from 1 August until 30 September 2017.

[ more ]

Summer School

This year, PTB and Braunschweig Technical University will again offer an international summer school which will be funded by the Helmholtz Fund.

[ more ]

EMRP/EMPIR

In 2017, there will be calls for papers on the following topics for new EMPIR projects: TP Industry, TP Fundamental, TP Normative, and TP Research Potential.

[ more ]

PTB News 3.2016PTB News 3.2016

The German part of the link uses commercially rented optical fibres and facilitiesof the German National Research and Education Network (DFN). TheFrench part of the link uses the Network for Education and Research, RENATER,which is operated by the GIP RENATER. Approximately midway,signals from LNE-SYRTE and PTB meet at the IT Centre of the University ofStrasbourg, so that the clocks of the two institutes can be compared there.(Fig.: PTB)

In the past few years, optical atomic clocks have made spectacular progress. They have become 100 times more precise than the best cesium clocks. So far, their precision has been available only locally, since frequency transfer via satellite cannot provide sufficient resolution. This has now changed thanks to a novel 1,400 km optical fiber link between Braunschweig and Paris. This link allows...

[ more ]
In the case of the LDA method, two laser beams are made to overlap. At the point where the beams cross, the measuring volume forms which allows fluid velocities to be measured. The velocity profile inside the pipe is measured on a measuring grid (yellow in the top picture) through a window; by integration, this provides the volume flow rate.

The decisive factor for increasing the energy efficiency of thermal power plants is to reduce the measurement uncertainty of the hot water volume flow rate measurement. The current uncertainty of approx. 2 % is not sufficient to optimize the control of power plants, which limits their efficiency. For this reason, PTB has developed a laser optical volume flow measurement standard (LVN) which allows...

[ more ]
Fluorescence scatter diagram for the identification of the CD34-positive stem cells, of the white blood cells (leukocytes) and of the calibration particles that have been added to the sample.

When transplanting stem cells, the dose is a decisive factor. To improve the determination of the dose by the measurement of the required concentration of viable stem cells, PTB has developed a reference procedure. It has been applied for the first time for comparison with results of the two methods that are currently used.

[ more ]
In this PTB laboratory, solar cells are irradiated with white light as well as withmonochromatic light (via the opening in the middle).

Conventional measurement procedures for determining the performance of solar cells make it difficult to obtain yield forecasts under real operating conditions. By means of a novel measuring setup which uses a laser-based spectral measurement procedure, PTB researchers have successfully characterized solar cells comprehensively enough that their yield can be calculated for any given climatic...

[ more ]
Reference microphone for airborne ultrasound (¼-inch measurement microphone mounted on an adapter to ½ inch) in the calibration setup at PTB’s acoustic anechoic chamber.

At PTB, a procedure has been developed for the calibration of microphones in the ultrasound range of up to 100 kHz. By means of this procedure, reference standards and working standards can be produced for laboratories in industry and research in order to ensure the traceability of airborne ultrasound. This new calibration service is now available.

[ more ]
Three of the new magnesium isotopic reference materials (Photo: Dora Kolar-Bosnjak, BAM)

Within the scope of the Avogadro project for the redefinition of the kilogram and of the mole, PTB has developed mathematical and experimental methods to measure extremely accurate and traceable isotope ratios. These very procedures had a decisive influence on the development of three magnesium isotope reference materials which BAM – Federal Institute for Materials Research and Testing, Germany,...

[ more ]
Production line of a 1 kg silicon sphere based on the example of the Avogadro project; representation of the different steps of the procedure: all the way from the ingot to the perfect sphere

Ultraprecise spheres exhibit form errors and roughness in the nanometer range. Their crystal surfaces are free of metallic contaminations and show no crystal structure damage. These properties place extremely high requirements on their manufacturing process. Through the use of a PTB invention, it is possible to produce spheres with small form errors (on the order of 20 nm) in a reproducible manner...

[ more ]
Semiconductor neutron monitor for pulsed radiation fields with a moderating sphere. The electronic unit can be easily miniaturized.

Pulsed radiation fields are used increasingly in novel medical accelerators and in fundamental research. Due to the high counting rate and detector saturation, radiation protection is confronted with new challenges. PTB's dosemeter is the first electronic radiation meter ensuring high metrological quality via high isotropy and low dead time for pulsed neutron fields. It consists of four silicon...

[ more ]
Set-up of the microelectromechanical system with two fiber interferometers

Free-standing thin membranes are used in numerous scientific and industrial contexts. The thickness of these membranes is often highly relevant for their pertinent function. PTB's new measurement device allows a quick and very accurate determination of the membrane thickness. For this purpose, the membrane is contacted from both sides. By integrating two fiber interferometers into the...

[ more ]

Awards

Harry Stolz Harry Stolz
the Managing Director of PTB’s Conformity Assessment Body, was elected the new chairman of NoBoMet on 20 April 2016. NoBoMet (Notified Bodies in Metrology) is the European coordination group of notified bodies for the European Directives for Measuring Instruments (2014/32/EU) and for non-automatic weighing instruments (2014/31/EU).

Wolf Fabian Fabian Wolf
a staff member of the QUEST...

[ more ]

PTB News 2.2016PTB News 2.2016

Schematic representation: Measuring the influence of thermal ambient radiation on the frequency of the trapped ion in the ytterbium clock. The “clock laser” (blue beam) excites the trapped ion (yellow) with a special pulse sequence. The resonance frequency of the ion is shifted by infrared radiation (here by an infrared laser, red beam). This can be measured by means of the clock laser.

With two clocks that are currently the best worldwide in terms of accuracy and stability, respectively, PTB is well-prepared for future tasks in fields such as fundamental physics where such clocks are necessary to detect possible changes in fundamental constants.

[ more ]
Space telescope Herschel (2009-2013) allowed fascinating insights into thebirth of stars. (Photo: ESA)

Space telescopes such as the infrared observatory Herschel of the European Space Agency (ESA) observe radiation in the far infrared. In this context, it is of vital importance that the instruments are cooled so that they do not emit disturbing infrared radiation. The mirrors of these telescopes, which are used at temperatures below –190 °C, are made of special, ultrastable ceramics. In a...

[ more ]
Top left: chip with two JAWS circuits (with a total of around 18 000 integrated Josephson contacts). Center: scanning electron microscope image of a JAWS circuit. Top right and bottom left: detailed enlargement of the circuit.

At PTB, the output voltage of a pulsedriven AC Josephson voltage standard has been significantly increased by using triple-stacked Josephson junctions, and by series connection of eight circuits with a total of 63 000 junctions; where previously obtained maximum output voltages were around an effective value of 300 mV, a standard value of 1 volt (important for metrological applications) has now...

[ more ]
The measured field distribution of the maternal heart (left) and the fetal heart (right). The red iso-field lines denote the areas with a positive sign of the magnetic field; the blue lines denote those with a negative sign. The position of each heart in this diagram is only approximate, as the exact positions were not determined precisely in this test measurement. Both heartbeat signals were measured simultaneously and then separated by means of a mathematical algorithm.

PTB researchers have measured the magnetic signals generated by the heart activity of the unborn child of a pregnant woman by using optical magnetic field sensors on her abdomen. They have demonstrated that the technology developed by the US National Institute of Standards and Technology (NIST) measures as reliably as other methods, and that it can even provide additional information. This might...

[ more ]
Present and future of alpha spectrometry under a defined solid angle: On the right, the current setup including source holder, diaphragm system and detector. In measuring operation, the detectoris flush at the outlet of the diaphragm system. On the left, the future detector can be seen. The appurtenant diaphragm system along with the source holder and the vacuum chamber are still under construction.

So far, the metrological characterization of alpha emitters has only been offered by a small number of national metrology institutes, as the manufacturing of the sources and characterizing measurement technology are very laborious. The determination of the activity of open alpha particle emitting sources has now been included in PTB’s range of services. As of now, such activity standards can be...

[ more ]

Awards

Frank Härtig

In January, the head of Division 1 (Mechanics and Acoustics) was made an honorary professor by the Institute of Ultra-precision Optoelectronic Instrument Engineering of the Harbin Institute of Technology (HIT), a university in Harbin, China, based on his work in the field of metrology and his pioneering developments in the field of traceability of metrological algorithms.

Harald...

[ more ]

Since 1 April 2016, Andrey Surzhykov has held the position of W3 Professor for Fundamental Physics of Metrology. This was preceded by a joint professorial appointment by PTB together with TU Braunschweig. One focus of Surzhykov’s work is the relativistic theory of atomic systems in order to find new approaches to testing fundamental constants and new approaches to inspecting the standard model of...

[ more ]

PTB News 1.2016PTB News 1.2016

(a) Conceptual set-up of the experiment with MgH<sup>+</sup>(orange) and Mg<sup>+</sup> (green) in a linear ion trap. The ionic crystal is cooled to the ground state via Mg+. An oscillating dipole force changes the motion state, depending on the rotation state of MgH<sup>+</sup>. This excitation is read out via Mg<sup>+</sup>. (b) Typical detection signal in which a quantum jump into the (J = 1) rotation state (transition from the red to the blue area) of the molecule and out of it (from blue to red) can be seen.

The QUEST Institute at PTB has, for the first time, succeeded in proving the quantum state of trapped and indirectly laser-cooled molecular ions without destroying the molecule itself or its internal state. In this way, quantum jumps which were induced by thermal environmental radiation could be observed directly in a single molecule, and a new form of spectroscopy could be demonstrated. The new...

[ more ]
Operating principle of the single-electron pump investigated: single electrons, depicted as red spheres, are captured while moving from one side of a conductor (in the figure, from the left-hand side) by a “dynamic quantum well” (between the “hills” of the potential landscape depicted here), and released toward the other side. The entire procedure is repeated at the clock frequency of the AC voltage, which raises and lowers the left-hand barrier of the quantum well.

Single-electron pumps are promising candidates for the realization of a future quantum current standard, and are the subject of intensive metrological research. By means of a novel, high-precision current amplifier, PTB researchers have succeeded in proving the quantization of a current of 100 pA supplied by a single-electron pump with an accuracy which had previously been unattained: within the...

[ more ]
Old (top) and new (bottom) method compared: The intensity of the X-rays is measured by means of ionization chambers. The measured ratio of the radiation intensity with and without the test object shows how much a layer of material (test object) attenuates the X-rays (red). With the conventional narrow-beam geometry (NBG), the scattered radiation (blue) is not detected by the ionization chamber; with the new inverse broad-beam geometry (IBG), the flat ionization chamber can detect it.

A new measurement method developed at PTB has been included in the updated version of the international series of standards IEC 61331. For the staff and the patients in medical X-ray diagnosis and nuclear medicine, the application of this standard, which has been elaborated under the leadership of PTB, represents a considerable improvement in radiation protection.

[ more ]
Capacitor systems (cross capacitor with partial capacitances C<sub>XC1</sub> and C<sub>XC2</sub> and cylindrical capacitor with capacitance C<sub>Zylinder</sub>) with corresponding pressure vessels to measure the dielectric constant of helium.

New measurements performed with PTB's dielectric-constant gas thermometer have yielded a value of 1.3806509 ⋅ 10–23 J/K for the Boltzmann constant k. The measurement uncertainty was thereby reduced to 4 parts per million (4 ppm). The new value is within 1.5 ppm in agreement with the current CODATA value (CODATA – Committee on Data for Science and Technology). Reaching the final step towards the...

[ more ]
Neutron monitor (left) during calibration with monoenergetic neutrons in the reference radiation fields of PTB.

The Wendelstein 7-X fusion experiment, which recently went into operation at the Max-Planck-Institut für Plasmaphysik (IPP) in Greifswald, is intended to demonstrate the suitability of stellerator-type fusion facilities for the production of energy. At the end of 2015, a helium plasma was generated for the first time. Producing plasmas with deuterium, in which neutrons are generated by nuclear...

[ more ]
Communication of individual modules within the system architecture

Measuring instruments often use large standard operating systems as their underlying software. This often makes software testing difficult as such systems contain a large number of bugs. A new system architecture developed at PTB makes use of the advantages of standard operating systems – such as a higher degree of functionality, an established user interface and executable drivers – yet still...

[ more ]

Awards

Manfred Peters
Prof. Manfred PetersThe former Vice President of PTB has been awarded the 2015 Ludwig Finkelstein Medal. With this distinction, the Institute of Measurement and Control, an internationally active organization of engineers which is headquartered in the United Kingdom, has honored his many years of substantial contributions to international metrology. The Institute further noted that Dr. Peters, whose...

[ more ]

PTB News 3.2015PTB News 3.2015

Electron orbital of a PTCDA molecule (left) and three-dimensional impulse distribution of the electrons after the photoemission (right). Assuming that there are free photoelectrons, the relation mainly consists in a Fourier transform (FT). The numbers 1 to 4 designate the four most important lobes of the distributi-on in the momentum space.

The three-dimensional distribution of electrons inside molecules has been made visible for the first time by means of electron spectroscopy. For this purpose, molecules which were aligned on a metallic surface were irradiated with vacuum-ultraviolet radiation, and the angle and energy distribution of the electrons that were detached by the photoelectric effect was measured. This procedure, which...

[ more ]
A gauge block screwed onto an end plate (top photo in the figure). Phase topography allows very accurate measurement of topographic changes within one wavelength. In this repre-sentation, the phase shifts occurring around integral multiples of the wavelength at the transitions between the base plate and the gauge block or in the vicinity of the screws have not been corrected so as to make the actual deflection visible. It can be clearly seen that both the gauge block surface (central area) and the base plate (area at the top and at the bottom) exhibit deformations that are due to the forces applied when tightening the joint.

Within the scope of the European re-search project “Thermal design and dimensional drift” (T3D), various joining technologies have been investigated at PTB for the first time with regard to their long-term behavior and to their reaction to thermal influences with a precision of approx. 1 nm.

[ more ]
Basic and degenerated exchange process

Atomic xenon can be temporarily encapsulated in molecular cages. Scientists from PTB have discovered that the direct exchange of xenon guest atoms — without the usual transition via a temporarily emptied host molecule — plays an important role here. This process could be used in new biomedical analysis and imaging procedures.

[ more ]
Cross section profile (red curve) of a silicon grating structure, determined optically. For com-parison, in the background: cross section profile of an identically manufactured specimen, measured by means of electron microscopy; the grating had to be cut perpen-dicular to the grating lines to take this picture.

A measurement method developed at PTB offers the possibility of measuring the size of grating structures that are clearly smaller than the optical wavelength used. Such structures play an important role, for example, in developing novel, more efficient lens systems and in manufacturing modern nanoelectronic components lithographically; however, they cannot be measured by means of conventional...

[ more ]
Silicon chip with arrays of different calibration structures (left); Raman mapping of a checkerboard pattern with a nominal periodicity of 2 µm (right). Horizontal and vertical profiles of the Raman signal intensity of silicon (dashed lines) are used to determine calibration factors for the (x,y) positioning unit of the Raman microscope.

A standard for the dimensional calibration of Raman microscopes, which was developed at PTB, allows both lateral calibration of the scanning facility and determination of the optical resolution. The quantitative analysis of Raman mappings thus becomes traceable chemical surface analysis.

[ more ]
Comparison of different data for the partial photoionization cross sections of the palladium L1 subshell. At higher excitation energies, the approach of an energy-independent ratio (red) shows deviations of up to a factor of 4.

By means of improved measurement procedures, PTB employees from the field of spectrometry with synchrotron radiation have succeeded – in cooperati-on with partners from industry – in experimentally confirming the different energy dependences of partial photoionization cross sections which could so far be predicted only by theoretic calculations. Due to this, the quantification approach of an...

[ more ]
MEMS nanoindentor system with a ruby sphere as an indentor

An MEMS-based nanoindentor, which was developed at PTB, allows simultaneous measurement of the indentation depth and of the indentation force. Tactile extraction of the indentation imprint is no longer necessary, which saves time. Due to the compact design and the possibility of precise mass production, it is possible to use a large number of sensors arranged in parallel. Since the MEMS can...

[ more ]
Correction for motion in an MRI system by means of UWB radar

In magnetic resonance imaging (MRI), the motions of the heart, respiration or other movements of the patient may affect the imaging quality. This problem can be solved by simultaneous irradiation with ultra-wideband (UWB) radar signals. Together with the TU Ilmenau, PTB has developed a system of antennae which allows the UWB technology to be used in innovative ultra-high-field MRI. Thus, the...

[ more ]
Various coaxial calibrators

Vector network analyzers (VNA) which, in high-frequency technology, calibrate the transmission characteristics of active and passive components in the frequency range of micro- and millimeter waves, can now be calibrated faster thanks to a new method developed by PTB. Instead of working with calibrators of the identical connector system, as has been the case to date, different – but compatible –...

[ more ]

Awards

Martin Kahmann

The Head of Department 2.3 “Electrical Energy Measuring Techniques” was awarded the DKE badge of honor for the numerous years he spent acting as a dedicated convener, spokesman, president and director of various subgroups of DKE and CEN as well as for his activities in favor of standardization at the national and the international levels.


Best Paper Award received by Thomas...

[ more ]

PTB News 2.2015PTB News 2.2015

Comparisons between atomic clocks with cesium and ytterbium, respectively, confirm the constancy of the mass ratio of protons to electrons. (Photo: PTB)

Are the fundamental constants really constant? Recent investigations carried out at PTB have shown that one essen-tial fundamental constant – namely the mass ratio of protons to electrons – can have changed only by a maximum of one part in a million over the age of our solar system (i.e. extrapolated over approx. 5 billion years). Previously, sci-entists deemed the possible changes to be twice as...

[ more ]
Horizontal cuts through GISAXS images before (top) and after (bottom) thermal processing. Each line represents an intensity profile (blue: low; red: high) at a specific angle of incidence of the X-rays onto the sample (i.e. at different penetration depths). The thermally processed sample shows the lack of signals of the surface-sensitive scattering at small ang-les of incidence, which suggests a loss of structure order at the surface. The order at larger angles of incidence, i.e. in the presence of scattering also coming from deeper layers close to the boundary with the substrate, remains unchanged.

The inner structure of technologically relevant polymer films in the nanometer range can, in principle, be easily investi-gated with scattering of synchrotron ra-diation in the X-ray range at wavelengths below 1 nm. The sensitivity of this meth-od is, however, often considerably limit-ed by additional scattering occurring at the boundary between the film and the substrate. In the PTB laboratory at...

[ more ]
As graphene is highly transparent, apart from the eight gold supply lines, it can hardly be differentiated under an optical microscope from the also transparent SiC substrate. Therefore, the quantum Hall structure is marked with a blue line. Contrary to the previous article, here, only the substrate is visible, the film itself is invisible.

The particular properties of the two-di-mensional conductor material graphene can also be exploited in the case of the quantum Hall effect on which extremely precise calibrations of the electric DC resistance are based worldwide. Graphene is, in many aspects, superior to all previously used materials. Now PTB has shown that graphene exhibits excellent properties also in the case of AC...

[ more ]
Height topography of the PZT sample (diameter: 15 mm, thickness: 2 mm) at 20 °C and 100 °C, with and without applied voltage.

The piezoelectrically induced length change in functional materials has been measured at PTB for the first time at high temperatures and with lateral resolution. For this purpose, a new sample environment was created which can be integrated into the existing interferometer for precise length measurements.
 

[ more ]
Probe style with sphere diameters from 8 mm to 1 mm for coordinate measuring machines

At PTB, the properties of diamond-coated probing spheres have been investigated for use with coordinate measuring machines (CMMs). The results show that using such probing spheres in CMMs, form measuring machines and also in contour measur-ing machines allows a considerable increase in the service life of the probing spheres as well as a reduction in the uncertainty of the measurements.

[ more ]
Measurement of the thermoelectric voltage difference across both junctions of a thermocouple, represented as the corresponding temperature difference (red curve). At a constant temperature difference, the result expected would be similar to the measurement of a short circuit (plotted here as a black curve for comparison purposes). Using the chopper-stabilized pre-amplifier (in the diagram after 8.5 hours) causes the noise amplitude to decrease by a factor of approx. 4, down to effectively 0.1 mK (peak to peak).

A chopper-stabilized amplifier with excellent properties has been developed at PTB and is used in a measurement set-up for the Avogadro Project to measure voltage on thermocouples. This has led to a reduction in noise amplitude by a factor of 4.
 
 

[ more ]
Data measured for the Planck constant (left of the dashed line). The error bars show standard uncertainties. As a result of the new adjustment method, the probability distribution for the value of the Planck constant is shown, together with the derived estimate and the corresponding standard uncertainty (right of the dashed line).

At PTB, a new statistical method has been developed to adjust inconsistent measurement data. Its advantages: more reliable results and a more realistic evaluation of the associated uncertainties. The procedure can, for example, be applied to determine fundamental constants.

[ more ]
Flow velocity measurement in a pipe (left: LDA probe; right: optical access)

Laser Doppler Anemometry (LDA) mea-sures the velocity in liquids optically – i.e. contact-free. A procedure developed at PTB to determine the position of the measuring volume considerably reduces the uncertainty of volume flow determi-nation when calibrating flow sensors by means of LDA. From the power of the backscattered laser light, the path of the interfering beams is reconstructed and the...

[ more ]
Überprüfung von Komponenten und Systemen auf ihre elektromagnetische Verträglichkeit (EMV) außerhalb von speziellen stationären Laboren

Test equipment developed at PTB allows, for the first time, components and systems to be tested with regard to their electromagnetic compatibility (EMC) without needing a special stationary laboratory. The main characteristics of this equipment are its simple operation and short measuring times. Diverse carrier frequencies enable the simulation of practically all relevant emitters of...

[ more ]
Example of a gap measurement standard with 3 selected sets of 4 spheres

Lengths on screw threads, toothed gears or other components exhibiting gaps are often measured in double-flank contact. The gap measurement standard developed at PTB detects and corrects influences which are due to self-centering probing or to double-point contact and are frequently neglected. On a thermally invariant base plate, at least four precision spheres are placed which were calibrated...

[ more ]

PTB News 1.2015PTB News 1.2015

These numerical simulations of the poroelastic model show the microdrops with different structures. From top right (clockwise): turbulent structures, rotating spiral waves, an antiphase oscillation, and an "even" wave running from right to left. The colours indicate regions of mechanical contraction (blue) and relaxation (red) which cause flow motions with velocities in the range from 0.1 μm/s to 1 μm/s.

In a new model for the formation of biological patterns, developed by mathematicians from PTB, cells are described as active porous and elastic materials. Simulations carried out using this model were able to reproduce experimentally wave patterns that had been observed in microdrops of the slime mould Physarum polycephalum and allow predictions for new experiments.

[ more ]
From the polycrystalline material from Russia, the Institute for Crystal Growth (IKZ), Berlin, grew a high-purity <sup>28</sup>Si single-crystal. It has an isotopic purity of 99.998 %. From this material, PTB produces nearly perfect spheres which will be analyzed to determine the Avogadro constant and Planck's constant.

The Avogadro constant and Planck's constant are the corner stones of the new system of units. The measurements with regard to these constants have been expedited within the scope of the international Avogadro Project; they are based on counting atoms in spheres made of pure silicon. A few months ago, Russian contracting laboratories supplied practically isotopically pure silicon so that the...

[ more ]
Scheme of the comparison of the optical strontium lattice clocks of PTB in Braunschweig and NICT in Tokyo via satellite. The arrows represent the up-(red) and the down-link of the two-way technique which is very well suited to suppress disturbances.

Intercontinental comparisons of atomic clocks can, at present, only be realized with the aid of satellites. The measurement noise occurring hereby determines the measurement time required. To compare the optical strontium lattice clocks of PTB with those of the Japanese Institute of Information and Communications Technology (NICT) in Tokyo, a new method with improved stability, developed by NICT,...

[ more ]
The SPICE spectrograph, mounted into the large vacuum tank at the MLS

The SPICE (SPectral Imaging of Coronal Environment) solar spectrometer is part of the Solar Orbiter mission of the European Space Agency whose start is planned for 2017. Within the scope of a research cooperation project which has been concluded with the Max Planck Institute for Solar System Research (MPS) and in cooperation with the Rutherford Appleton Laboratory (RAL) in England, the SPICE...

[ more ]
Top: The profilometer in front of a nozzle 800 μm in diameter. The nozzle opening itself is not visible. The cantilever is 7.5 mm long. It consists of two cantilevers that are glued together. Bottom: Measured topography of the nozzle.

A profilometer, which was developed by PTB together with two cooperation partners, has allowed the inner surfaces of small nozzles with diameters in the micrometre range and a high aspect ratio to be successfully characterized for the first time.

[ more ]
Two-channel ULCA prototype (front view with SMA connectors)

A handy picoamperemeter has been developed at PTB which is able to traceably measure extremely small currents with unprecedented accuracy. The Ultrastable Low-noise Current Amplifier (ULCA) exceeds the accuracy of previously available picoamperemeters by about two orders of magnitude.

[ more ]

The introduction of the 450 mm technology for wafer production and the further scaling-down of critical dimensions require improved X-ray analytical methods. PTB has therefore designed a complementary metrology chamber to characterize 450 mm wafers; its core component is a multi-axis manipulator whose patent is pending. By spatially stacking all mobile components, this chamber allows several X-ray...

[ more ]

Measuring outgassing rates of vacuum components reliably and quantitatively has become increasingly important over the past few years. With PTB's new reference outgassing sample, such outgassing rate measuring systems can be calibrated and traced back to a national standard. Thanks to its compact set-up, it can be used in a variety of scenarios. It provides a precisely known gas flow which is...

[ more ]

How can highly sensitive optical fibres be introduced into vacuum vessels so that they can be rotated in the narrowest of spaces and displaced longitudinally? A new development by PTB helps solve this problem. It enables optical fibres to be positioned and subsequently adjusted. Hereby, leakages, which may occur in conventional designs, are minimized, the risk of cracking is reduced due to a...

[ more ]

Auszeichnungen

Harald TelleHarald Telle
erhielt den 2014 I.I. Rabi Award für seine Pionierarbeiten bei der Anwendung optischer Frequenzkämme zur phasenkohärenten Frequenzmessung.

 

 

 

 

Franziska RennerFranziska Renner
Die Mitarbeiterin des Fachbereichs 6.2 Dosimetrie für Strahlentherapie und Röntgendiagnostik erhielt den Elekta-Preis der Deutschen Gesellschaft für Medizinische Physik e. V. für ihre Arbeit „Benchmark experiment to verify...

[ more ]

PTB News before 2014

PTB News before 2014PTB News before 2014