Optimized design for main switch of 1 MV low-impedance accelerator

The structure of a 1 MV low-impedance accelerator and the design principles of its main switch were introduced. Optimized design and simulation of the oil switch, which was selected as the main switch, were carried out. The simulation showed when the switch was working at 1 MV, the discharge inductance was about 100 nH, the distributed capacitance was 150 pF, and the charging inductance was 360 nH. No unacceptable influence was caused by those distributed parameters. Simulation also showed that the electric field inside the main switch was safe, that is, no flashover would happen at the oil-nylon interface. The low-impedance accelerator was assembled with the optimized oil switch and produced 700 kV, 70 kA electron beams with 150 ns pulse width (FWHM). Preliminary tests show that the switc