Production of the low loss, low voltage and high current switch for 77K with multi parallel connected MOSFETs and the application to the superconducting coil charging circuit

摘要

To make a quite low-resistance switch operated at 77K in liquid nitrogen bath, we utilize a multi-connected MOSFETs in parallel. The rated current and its resistance of the fabricated switch is 500A/400μΩ using 100 MOSFETs. And the excitation test of a superconducting coil was carried out using the proposed low-voltage/high current DC power source [1]. Test results show that excitation up to the quench current of 42A of the superconducting coil is made possible by the low-voltage of 0.3Vrms.