Upgraded pulsed magnetic field generator for Shenguang-II laser facility toward 30 T

Abstract

The pulsed magnetic field device for Shenguang-II (SG-II) laser facility was upgraded to obtain stronger magnetic field with longer rising time, and to facilitate single person operation. The upgraded magnetic field device adopts a modular design that allows for easy adjustment of individual component and parallel connection of multiple devices. Both the capacitor bank and the gas switch operate in atmosphere environment, and are no longer sealed in enclosure filled with insulating gas. Combined with plug-and-play design, the installment and operation are simplified markedly. The capacitor bank module can be expanded flexibly up to six times the original device. Besides stronger magnetic field with longer duration, large capacitance also allows the device to be compatible with various forms of magnetic field coils and extend the range of magnetic field parameters. Pulsed magnetic fields of 9.6 T and 12.6 T with >1 μs rising time are generated using double- and triple-turn Cu coils of 12 mm diameter at 30 kV charging voltage, at which the intensity of magnetic field is mainly limited by the yield strength of Cu coils. Using an inductively coupled coil made of higher yield strength material of BeCu, the magnetic field strength is further increased to 32 T with >3 μs rising time at 35 kV charging voltage.