Discharge instability at early stage of plasma column formation in tokamaks

摘要

In our paper we study the breakdown physics and current rump in tokamaks in wide range of parameters in 0D model. It is shown that the current-voltage curves has the S-shape. If the loop voltage is greater than critical value than discharge goes from low-current stage to high-current stage. If voltage is less than critical value there are both dumping and steady-state oscillations with large amplitude. The breakdown voltage increased versus gas pressure and decreased versus minor plasma radius.