Adaptive current sources and feedback applied to the cryogenic current comparator

Abstract

A novel current source for the cryogenic current comparator (CCC) is presented which is adaptable to many coil, resistance and filtering configurations. The effect of both current feedback from the SQUID and voltage feedback from the detector are examined and incorporated into the design. The advantages of the new system are examined in terms of flux tracking, leakage, self checking, accuracy and flexibility. The system has been used at NRC over the resistance range of 1 /spl Omega/ to 1 M /spl Omega/.<>