Long pulse ion source discharge based on plasma density feedback

The influence of plasma density on plasma discharge has been introduced. In order to obtain the long pulse discharge, the Langmuir probe was employed to measure the plasma density and to control the plasma discharge with feedback. The hardware and software of the control parts were designed and the plasma density feedback control system was established based on the Langmuir probe measurement. Besides, the system was applied to the ion source plasma discharge experiment successfully. The long pulse discharge of 4.5 s was got and it provides the fundamental for the steadystate operation of neutral beam injection in the future．