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Single-photon detectors are being used more and more frequently for applications such as quantum communication, quantum computing and quantum imaging as well as for experiments in the fields of astrophysics and materials science. To detect the single photons, PTB’s concept requires the detector to be constructed from a two-dimensional superconductor. A hole pattern of non-superconducting areas is integrated into the superconductor. This geometry allows an absorbed photon in one of these areas to induce an avalanche-like transition to normal conductivity in the detector. It induces an excess voltage, which allows the absorption of the photon to be detected.

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Kibble balances weigh using a voice coil actuator with electromagnetic force compensation. For the calibration of Kibble balances with a larger measuring range (from grams to kilograms), optical methods are used. A new method developed at PTB allows the correction of errors caused by tilting mirrors, the so-called Abbe errors. This calibration procedure has been tested at PTB and can also be used for other applications where the Abbe error occurs. (Technology Offer 538)

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Cryostats are devices in which defined and spatially limited areas or components are cooled down to a predefined and very low temperature, e.g. below -269 °C (4.2 K). A novel device designed for the variable temperature adjustment of special flow cryostats based on pneumatic motors made of plastic and of other components made of non-magnetic materials can minimize electromagnetic interference fields. This enables direct, high-precision SQUID measurements of weakly magnetic materials that cannot be achieved using conventional optical methods or neutron scattering techniques. The cryostats are inexpensive and easy to manufacture. (Technology Offer 521)

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Kryostate sind Vorrichtungen, in denen definierte, räumlich begrenzte Bereiche bzw. Bauteile auf eine vorbestimmte, sehr niedrige Temperatur beispielsweise unter –269 °C (4,2 K) abgekühlt werden. Durch eine neuartige Vorrichtung zur variablen Temperatureinstellung spezieller Durchflusskryostate auf Basis pneumatischer Motoren aus Kunststoff und weitere Komponenten aus nichtmagnetischen Materialien können elektromagnetische Störfelder minimiert werden. Damit werden direkte, hochgenaue SQUID-Messungen schwach magnetischer Materialien ermöglicht, die mit herkömmlichen optischen Methoden oder Neutronenstreuungstechniken nicht durchgeführt werden können. Die Kryostate sind kostengünstig und einfach in der Herstellung. (Technologieangebot 521)

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PTB has determined the surface of a life-size cow model. This has enhanced the experience in the dimensional measurement of natural or near-natural material, which will be beneficial to future metrological challenges.

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In geochronological sciences, for example when determining the age of rocks, potassium-40 is known to be one of the most important tools. To this end, its half-life and further decay data must be known as accurately as possible. These have been redetermined in sophisticated experiments.

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Working within an industrial cooperation project, PTB has developed a novel metrology system for the quantum-based generation and measurement of voltage signals. The system is based on a pulse-driven Josephson standard, the Josephson arbitrary waveform synthesizer (JAWS), and has been designed for deployment in a wide variety of applications. This system can be used not only as a quantum-based voltage generator, but also as an ultra-accurate instrument for measuring DC voltages and AC voltage signals. A prototype has been successfully tested at PTB for signal frequencies up to 100 kHz.

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Highly reflecting mirrors are an essential component of the most precise optical interferometers, which are used, for example, for the detection of gravitational waves or in optical atomic clocks (to reduce the linewidth of lasers). These applications are inherently limited by Brownian noise, where the thermal motion of the particles in the mirror leads to fluctuations of the reflected light wave. It is expected that novel GaAs/AlGaAs Bragg reflectors will substantially reduce this noise contribution. Due to newly discovered noise processes, however, the improvement at low temperatures is only small compared to conventional mirrors.

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Since December 2022, cash gaming machines have been approved by PTB in digital form only. The transition to digital processes increases efficiency and saves time in the approval procedure for both PTB and applicants.

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For 25 years now, PTB has been supporting the development of extreme ultraviolet lithography in Europe by characterizing optical coatings. Since 2019, this European technology has been used in the mass production of high-quality semiconductor components. With this application, the requirements placed on the quality of the measurements have once again significantly increased. To meet this challenge, a new and improved reflectometer has now been put into operation.

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