Spectroscopic Determination of the Electrostatic Potential Profile in a Plasma-Prefilled Ion Diode.

摘要

The electrostatic potential profile in the accelerating gap in a plasma-prefilled magnetically insulated intense pulsed ion beam diode has been determined using laser induced fluorescence spectroscopy. Results for a 300 - 400 kV planar diode are presented, both with and without an electron emitting vane protruding from the cathode. In both cases, a 5-6 mm accelerating gap forms in the 10 to the 12th power-10 to the 13th power/cc plasma in a few nanoseconds. The experimental potential profiles are not consistent with electrons confined to a sheath near the cathode. Rather, electrons are required throughout the gap to explain the observations.