Turn-o Energy Reductions of Superconducting Power Electronics Devices (S-PED)

We made some thermally controlled superconduct-ing electronics devices (S-PED). They work up to 50 A, 50 Hz and 25 A, 100 Hz as a full wave rectifying circuit and can be applied to the power supply of the superconducting magnets. We mesured the turn o characteristics of S-PEDs, the results are that the gate trigger energy to turn o is larger than the heat in-leak to cold part with same class current leads. To reduce the switching loss, we made some trials to reduce the thermal resistance between channel and gate. Key words: superconducting magnet, rectier, power supply, switching device, thermal resistance