Subcable test facility

A subcable test facility was prepared to study ac losses and stability of subsize cables under the pulsing magnetic field of a 40-kJ split pair coil. A G-10 cryostat fabricated for the system has an inner diameter of 31 cm and is 170 cm deep. An 80-kW power supply for the coil has a pulsing mode of triangular operation. Another 500-kW power supply, rated for dc operation at 400 V and 1250 A, can have pulsing modes of triangular, trapezoidal, or (B + B) superimposed. The ac losses of a superconducting composite strand with CuNi outer sheath were measured. Coupling losses among the strands were not significant because of the outer sheath.