NIST scientists are working to miniaturize the devices, raise the operating temperature to more easily attainable levels, and find ways to reduce the instruments’ cost. The equipment associated with low temperature operation plus necessary electronics means both systems are about the size of a washing machine. Because the Josephson junctions consist of superconducting components, the devices must operate at low temperatures (4 kelvins, -270 C, -452.2 F). The 10V PJVS chip is 12x17 mm, containing 32 arrays and 265,116 Josephson junctions, and the 2V JAWS chip is 10x15 mm, containing eight arrays and 102,480 Josephson junctions. Advantages Over Existing Methodsīoth the DC and AC voltage standards are produced in the Boulder Microfabrication Facility. Recent improvements in NIST’s PJVS have reduced measurement uncertainties in comparing DC output from two nonprogrammable Josephson Voltage Standard (JVS) instruments to less than one part in 10 billion, an achievement with worldwide impact on increased confidence in test results. These technologies are now poised to progress to the next level at higher voltages and AC frequencies. In May 2019, as a result of the redefinition of SI units, Josephson standards became the authoritative means by which to realize the volt. Both are primary standards - that is, they do not need to be calibrated against any other standards because they are based on a fundamental, invariant quantum phenomenon. Mature versions of NIST’s PJVS and JAWS systems are currently available through the Standard Reference Instrument program. The other is the Josephson Arbitrary Waveform Synthesizer (JAWS), which generates user-determined AC waves of various shapes (such as the square waves used in digital switching) at 2 V and frequencies of millions of cycles per second. One is the Programmable Josephson Voltage Standard (PJVS), which generates user-specified DC voltages from -10 V to 10 V. Two of these devices are both well known and trusted by the research and development communities. NIST researchers are continuing to develop instruments that are already “gold standards” for generating output voltage with maximum accuracy within a certain range.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |