[volt-nuts] Homebrew JJ voltage standard
Dr. Frank Stellmach
drfrank.stellmach at freenet.de
Thu Sep 9 20:15:04 UTC 2010
the crucial thing is definitely the JJ multi junction structuring, let
it be a Nb-Al/Al2O3 Superconductor @ 4.2K of liquid He(4) or the HTC -
YBCO @ 77K of liquid Nitrogen. Can't be done at home, and is for sure
A can of 50l liq. He is not that expensive compared to the cost of the
JJ element and the rest of the electronics.
At the Juelich institute, associated to the RWTH Aachen, Technical
University, and my Physics Alma Mater, they have shown that HTC
superconductors also can give a reasonable good accuracy of about 10^-8:
Anyhow, this is also not accessible for us as a homebrew standard, I think.
Too much expensive gear for high vacuum, sputtering and structuring is
necessary for the production of such a device.
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