Model improvement and analysis of NBI power supply under breakdown condition

Abstract

Breakdown commonly occurs in the acceleration grids of the NBI system. It will cause destructive effects on the accelerating grids, and the generated transient overvoltage and current will threaten the normal operation of the acceleration grid power supply (AGPS). Therefore, it is very necessary to model the circuit to analyze the effects of breakdown on the NBI system. However, the current models are not accurate enough and are likely to have insufficient knowledge of the consequences of breakdown. In this paper, a series of improvements are made to the model by analyzing in detail the change process of AGPS during breakdown and correcting the model parameters in conjunction with the existing AGPS design scheme. Subsequently, the key indicators of the NBI system under breakdown are listed. The impact of breakdown and the need for some protection are assessed based on the results of these indicators. The results of this paper are instructive for the design and breakdown protection of future NBI systems.