Results from a detailed calculation of the sensitivity of a cryogenic current comparator

A detailed calculation of the sensitivity of a cryogenic current comparator (CCC) has been completed. The model accounts for the current distributions on the closed external shield and the overlapped shield around the windings. Additional refinements to the model lead to excellent agreement (typically better than 5%) with sensitivity measurements for a wide range of CCC geometries. We demonstrate that generally the best strategy for significantly improving the overall gain of a CCC is to increase the number of windings in the toroid at the expense of a reduction in the sensitivity