Cryocooled 10 V Programmable Josephson Voltage Standard

Improvements in fabrication and packaging of our 10 V Programmable Josephson Voltage Standard circuits have enabled the successful operation of these devices on a cryocooler. Limited cooling power and temperature oscillations at the chip must not compromise the accuracy of the quantized voltage steps. Flat-spot measurements of quantized voltages produced with all of the sub-arrays when the chip is biased at a temperature of 4.35 K produced a step width of 0.78 mA. This result was obtained with a cryostat that uses a modest 1.3 kW air-cooled compressor that generates 180 mW of cooling power at the chip.