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PTB News

Three times a year, PTB News provides topical information from the varied spectrum of activities of the Physikalisch-Technische Bundesanstalt (PTB) consisting of fundamental research, legal metrology and PTB's various activities in the service of the economy.


Brain pacemakers are very helpful for diseases such as Parkinson’s. But an implant can cause dangerous
tissue heating during an MRI scan. (X-ray image; source: Wikimedia Commons)

With well over 100 million examinations per year worldwide, magnetic resonance imaging (MRI) is the second most important medical imaging method. However, patients with implants often have to refrain from this life-saving diagnostic option or accept a lower image quality. Especially with active implants, such as cardiac pacemakers and neurostimulators, MRI scanning can lead to dangerous tissue...

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Schematic representation of the measuring room with a few sensors. By means of this new method, temperatures and their uncertainties can be estimated at any desired location based on local sensor data.

In principle, sensor networks and appropriate interpolation methods can be used to determine the temperature at any desired location in a room. The reliability of such interpolated data was tested at PTB.

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As part of the search for dark matter, three atomic clocks were compared, two of which use different transitions in the same Yb<sup>+</sup> ion stored in a single-ion trap (left). The third optical clock uses approx. 1000 neutral strontium ions in an optical lattice (right).

Can dark matter interact with photons and influence atomic structure? A comparison of two different kinds of optical atomic clocks at PTB has improved existing experimental detection limits for a possible coupling by more than an order of magnitude and over a wide range of dark matter particle mass. While no evidence of a dark matter coupling has been found, the work brings us closer to...

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Simulation of electronic collision circuit: Two electron sources (S1, S2) simultaneously send indistinguishable electrons down counter-propagating paths. The electrons’ movement within the potential of an electronic beam splitter can be controlled precisely due to their mutual interaction. The outcome is detected by two detectors (D1, D2) that can determine the arrival of an individual electron.

Targeted collision of single photons or electrons enables a sensitive measurement method that can be used to investigate and control the way in which they influence each other. This reduction to single sharp signal impulses allows the measurement resolution to be improved and new components to be created for quantum information processing. In nanostructured semiconductor circuits, two separate...

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Combining PTB’s digital calibration certificate (DCC) with DAkkS’s accreditation symbol contributes to widely automating production processes.

Following a successful pilot phase, accredited calibration laboratories will be able to apply for the digital calibration symbol starting in late March 2024 and thus provide digital proof that they are accredited. In combination with the digital calibration certificate developed by PTB, it serves as machine readable, tamper-proof and verifiable evidence of calibration which will ultimately replace...

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The calibration principle is impressively easy: The microphone to be tested is mounted on this disc. It rotates vertically and therefore exposes the microphone to a sinusoidal change of altitude. The velocity of the disc determines the pitch.

There is currently no reliable infrastructure for traceable calibration of measurement devices and sensors for measuring infrasound. As an important development step to improve this situation, a novel primary measuring setup for infrasound was set up at PTB. This new setup uses the decrease of ambient air pressure with increasing altitude as an excitation signal.

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The superconducting layer of a trap electrode (left) allows the photon detection of an ion that is trapped in a trap potential.

A quantum computer uses qubits to perform its operations. To date, ion traps have proved to be one of the best ways of manufacturing, storing and manipulating qubits. The concept developed by PTB is based on integrating components that have been separate until now. These are the sensor for photon detection and the trap electrode, which is made of a superconducting layer. The two components have...

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Three-axis Helmholtz coil system and a magnetic resonance detector in a shielded room for measuring magnetic flux density

Just how strong a magnetic flux density is can be determined with high precision by using magnetometers that are based on the principle of measuring nuclear magnetic resonance. PTB’s new method is particularly well suited for low fields within magnetic shields. This method uses hyperpolarized samples and drives at least two Rabi cycles – each one with different excitation frequencies. The new...

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ELVIS – the mobile test lab

If a charging station cannot be taken to a laboratory, then the laboratory must go to the charging station. The electric vehicle charger inspection system (ELVIS) is a fully equipped lab that can examine any installed electric charging station in detail. And it can do this whatever the weather and wherever the location because ELVIS is mobile. In addition, ELVIS provides testing techniques for...

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 Frank Lienesch Frank Lienesch, the head of Division 9, Legal and International Metrology, has assumed the German chair of the “International Committee of Legal Metrology” (CIML) after Roman Schwartz.

Roman Schwartz Roman Schwarz, the former vice president of PTB and president of the International Committee of Legal Metrology (CIML) since 2017, was presented with an honorary OIML membership as...

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Following a successful assessment, the German-Japanese Center for Time, Constants and Fundamental Symmetries (TCFS) is ready to begin its second five-year term during which it will strengthen cooperation between German and Japanese institutes even further. The international experts develop the most sensitive instruments for fundamental measurements in atomic and nuclear physics, antimatter and...

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Explaining AI

Artificial intelligence, usually in the form of neuronal networks, is already frequently being applied to express recommendations for human decision-makers or to simply make decisions itself. However, which criteria are used to reach a decision is often unclear. In line with the need to make AI explainable, the first pre-standard on AI explainability has been published with PTB’s participation....

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IMEKO 2024

Logo für den großen Weltkongress der Internationalen Messtechnischen Konföderation (IMEKO) vom 26. bis 29 August in Hamburg

The IMEKO World Congress in Hamburg welcomes you with a variety of metrological events - including three workshops on the topics of digitalization (26.8.), quantum technology (27.8.) and the UN Sustainable Development Goals (28.8.). On Thursday (29.8.), you can choose from various Company Tours in Hamburg, for example at DESY or XFEL. Friday (30.8.) is reserved for a trip to the PTB in...

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