Dynamic response of recombining detached plasma to electron beam injection

Dynamic response of recombining detached helium plasma to high-energy electrons was investigated in the linear plasma device NAGDIS-II by introducing an electron beam source. A square wave bias was applied to the tungsten electrode to generate a pulsed electron beam with controlled beam energy. At high beam energy condition, a large increase in the target ion flux and different-shape time evolutions between emissions from low- and high-excited states were observed. From the analysis using a collisional radiative code applicable to two electron temperature components, qualitative changes were explained by contributions due to the excitation process from the ground state by the electron beam and the volume recombination process due to the parameter change of bulk plasma.