Closed-drift accelerator with improvement of plasma instability and magnetic-pole overheating

Numerical and experimental researches on a enhanced closed drift accelerator are conducted by highlighting on propellant temperature, plasma parameters and channel-wall condition in order to suppress plasma instability and magnetic- pole overheating, and the following findings are obtained: "Average length of ionization-zone" introduced as a new physical parameter, which could be varied by neutral particles velocity, is correlated conversely with large-amplitude of plasma instability that should be solved to improve the operational stability and the system durability. Then we propose a closed drift accelerator with new design concepts giving simultaneous solution for reducing the instability and the accelerator core overheating. And the mechanisms of controlling amplitude are clarified from the viewpoint of the spatiotemporal variations of plasma parameters and electromagnetic field when neutral species temperature is changed.