First Direct Comparison of a Cryocooler-Based Josephson Voltage Standard System at 10 V

Schubert, M.; Starkloff, M.; Meyer, Matthias; Wende, G.; Anders, S.; Steinbach, B.; May, T.; Meyer, H.‐G.

doi:10.1109/tim.2008.2008466

Cited by 13 publications

(11 citation statements)

References 12 publications

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“…At this higher temperature, the cryocooler used here has a capacity in excess of 1 watt with only an aircooled compressor running on a single-phase power outlet. Conventional Josephson Voltage Standard (CJVS) circuits have also been successfully implemented on cryocoolers [5][6]. Since no dc current is required to generate quantized voltages with the hysteretic JJs of CJVS circuits, only the microwave bias contributes to the power dissipation on the chip, typically less than 100 mW.…”

Section: Cryocoolermentioning

confidence: 99%

Cryocooled 10 V Programmable Josephson Voltage Standard

Rüfenacht

Howe

Fox

et al. 2014

29th Conference on Precision Electromagnetic Measurements (CPEM 2014)

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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 aircooled compressor that generates 180 mW of cooling power at the chip 1 .

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Section: Cryocoolermentioning

confidence: 99%

Cryocooled 10 V Programmable Josephson Voltage Standard

Rüfenacht

Howe

Fox

et al. 2014

29th Conference on Precision Electromagnetic Measurements (CPEM 2014)

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show abstract

“…The superconducting electrodes of the junctions are made of niobium and thus have to be operated below 9.1 K. Liquid helium is used as a cryogen in most apparatus, although some very good results have been obtained with cryocooler-based systems where the temperature set point can be higher than the equilibrium temperature of liquid helium [18,30]. For those JVSs, the array and its leads are permanently thermally anchored and therefore do not offer any flexibility for changing parameters such as in the 'floating mode' of the array from the ground potential or the change of the probe immersion to modify the RF signal propagation and/or thermal EMFs.…”

Section: Cryogenic Operating Temperature and Magnetic Shieldmentioning

confidence: 99%

BIPM direct on-site Josephson voltage standard comparisons: 20 years of results

Solve¹,

Stöck²

2012

Meas. Sci. Technol.

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The discovery of the Josephson effect has for the first time given national metrology institutes (NMIs) the possibility of maintaining voltage references which are stable in time. In addition, the introduction in 1990 of a conventional value for the Josephson constant, KJ-90, has greatly improved world-wide consistency among representations of the volt. For 20 years, the Bureau International des Poids et Mesures (BIPM) has conducted an ongoing, direct, on-site key comparison of Josephson voltage standards among NMIs under the denominations BIPM.EM-K10.a (1 V) and BIPM.EM-K10.b (10 V) in the framework of the mutual recognition arrangement (CIPM MRA). The results of 41 comparisons illustrate the consistency among primary voltage standards and have demonstrated that a relative total uncertainty of a few parts in 1010 is achievable if a few precautions are taken with regard to the measurement set-up. Of particular importance are the grounding, efficient filters and high insulation resistance of the measurement leads, and clean microwave distribution along the propagation line to the Josephson array. This paper reviews the comparison scheme and technical issues that need to be taken into account to achieve a relative uncertainty at the level of a few parts in 1010 or even a few parts in 1011 in the best cases.

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“…The first 1 V array had a total of 1474 PbInAu/PbO x /PbAu (B) SIS jj driven at 90 GHz [30]. Junction materials such as NbN/MgO/NbN (C) [31] and Nb/AlO x /Nb (D) [32][33][34][35][36][37][38][39][40][41] were successfully used as well (cf table 2).…”

Section: Materials and Geometrymentioning

confidence: 99%

A review of Josephson comparison results

Wood

Solve

2009

Metrologia

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In March 2009, the Consultative Committee for Electricity and Magnetism (CCEM) reviewed and re-endorsed its recommendations originally proposed during its 25th meeting (April 2007) for changes in the SI electrical units (Recommendation E-1). Among its considerations, the document stated that the representation of the volt using the Josephson effect and the conventional value of the Josephson constant, K J−90 , has provided practical, accessible, reproducible, low noise and highly linear references worldwide since 1990. We summarize the measurement results of comparisons between Josephson voltage standards that help support this statement, especially concerning the accuracy and the simplicity of the Josephson relationship between voltage and frequency. We also detail a list of influence parameters and the ranges over which the Josephson relationship has been tested.

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First Direct Comparison of a Cryocooler-Based Josephson Voltage Standard System at 10 V

Cited by 13 publications

References 12 publications

Cryocooled 10 V Programmable Josephson Voltage Standard

Cryocooled 10 V Programmable Josephson Voltage Standard

BIPM direct on-site Josephson voltage standard comparisons: 20 years of results

A review of Josephson comparison results

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