论文信息 - Cryogenic current comparator measurements at 77 K using thallium-2223 thick-film shields

Cryogenic current comparator measurements at 77 K using thallium-2223 thick-film shields

Several different magnetic shield geometries were used to study cryogenic current comparator (CCC) operation with thallium-based thick film superconducting shields at 77 K. These shields are found to have good magnetic shielding properties and to support low-level persistent currents. This study investigates geometric properties of the magnetic coupling between the CCC and one type of superconducting quantum interference device (SQUID) sensor. The sensitivity of the SQUID and its coupling to the shielding currents limit ten-to-one CCC resistance ratio measurements to approximately 0.2 /spl mu//spl Omega///spl Omega/ in relative uncertainty.

Randolph E. Elmquist

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