Measurements of localized potential profiles by LIF polarization spectroscopy in an inertial-electrostatic confinement discharge

Spatial distributions of the electric field were measured in inertial-electrostatic confinement plasmas generated in a glided cylindrical hollow cathode in He gas as a function of the applied voltage using laser-induced fluorescence polarization spectroscopy to obtain profiles of the potential and the charge density. With increasing applied voltage, the potential difference between the center of the plasma and the cathode decreased, while a virtual anode due to converging positive ions was clearly appeared at the center of the cathode. These are probably caused by the increase in the number of electrons emitted from the cathode surface due to the increasing ion bombardment with increasing applied voltage.