New 10V Programmable Josephson Voltage Standard (PJVS) and its Application for the 2014 NCSLI JVS Interlaboratory Comparison

The National Conference of Standard Laboratories International (NCSLI) is scheduled to start the 10th Josephson Voltage Standard (JVS) Interlaboratory Comparison (ILC) in early 2014. NASA’s Kennedy Space Center (KSC) which began operating a 10V Programmable Josephson Voltage Standard (PJVS) in 2010 is a pivot lab candidate for the NCSLI JVS ILC. We propose to use the NASA PJVS as a transfer standard for the intercomparison in addition to using the group of Zeners that were used in the previous ILC. The superior stability of the 10V PJVS’s voltage step enables it to perform the same tasks as the Zener standards and to also improve the efficiency and effectiveness of the ILC through a direct comparison. Recently, a comparison between a conventional JVS and the NIST 10V PJVS was performed by NIST in order to verify the performance of the NIST 10V PJVS. The mean difference between the two systems at 10V was found to be -0.49 nV with a combined standard uncertainty of 1.32 nV (k = 1) or a relative combined standard uncertainty of 1.32 parts in 1010. The advantage of using the 10V PJVS is that a participating lab is able to make comparisons using its conventional JVS system against the 10V PJVS in the same manner as the measurements for Zener standards are performed. Due to the quantum nature of the 10V PJVS, its superior accuracy and stability will improve the uncertainty of a JVS comparison for the direct comparison participants to a level of a few parts in 1010 at 10 V. This would be an improvement over the 2011 ILC which reported an expanded uncertainty with 95% confidence limits of +220 nV and -150 nV.