Re. Elmquist et Rf. Dziuba, HIGH-TEMPERATURE SUPERCONDUCTOR CRYOGENIC CURRENT COMPARATOR, IEEE transactions on instrumentation and measurement, 44(2), 1995, pp. 262-264
NIST is developing a cryogenic current comparator (CCC) to operate at
77K, using high-temperature superconductor (HTS) ceramic shielding mat
erial and an HTS-based superconducting quantum interference device (SQ
UID) detector. The shielding properties of at least two polycrystallin
e oxide HTS materials appear sufficient for use in a high-accuracy CCC
. A measurement of current-linkage error, a figure of merit for CCC de
vices, is made for one type of HTS CCC. The design of a second HTS CCC
which uses improved magnetic shielding is described.