BREAKDOWN CONDITION IN A TOKAMAK
托卡马克装置的击穿条件

An experiment has been conducted on CT-6B tokamak in order to study the effect of discharge conditions, such as filling gas pressure, toroidal field, stray magnetic fields and loop vvoltage, on the breakdown. It is found that the dependence of breakdown voltage on the vertical stray field is obviously different from that on the horizontal stray field. The main experimental results are discrepant from the Townsend discharge model. The distribution function of electrons during the breakdown phase has been solved by using a Monte-Carlo code and the breakdown condition deduced from the Townsend model has been revised.