Snubbers for Limiting and Mitigating Fault During Acceleration Grid Breakdown for Neutral Beam Systems

Abstract

Typical Neutral Beam (NB) system is based on the acceleration of negative ions; designed to inject 60A of Neutral beam at (-) 100kV with specified modulation in to the plasma. The acceleration grids operate very close to breakdown. During conditioning and normal operation of the injector, breakdowns can occur frequently and unpredictably. It is important to limit as much as possible the energy flowing into the grids. Core snubbers (annular disc of magnetic material) are considered to be most promising options for limiting the fault energy during the breakdowns in the accelerators. This paper presents the study and overview of typical NB system. An experimental setup is been used to study and characterize the actual size CRGO core snubber. Results are discussed to investigate the feasibility of CRGO cores.