Paper PS-ThP7
Diagnostics in a Continuous Electron Beam-Generated Plasmas

Thursday, October 18, 2007, 5:30 pm, Room 4C

The US Naval Research Laboratory has developed a plasma processing system that relies on a magnetically collimated, sheet of multi-kilovolt electrons to ionize the background gas and produce a planar plasma. High-energy electron beams are efficient at producing high-density plasmas (n_e > 10¹⁰ cm^-3) with low electron temperatures (T_e < 1.0 eV) over the volume of the beam, resulting in large fluxes of low-energy ions (< 5 eV) at surfaces located adjacent to the electron beam. Most systems under developed at NRL use a hollow cathode pulsed to high voltages to produce the electron beam, which of course, results in a modulated plasma. We have recently developed a continuous electron beam source and are investigating the plasmas produced using this source. In this work, we discuss the bulk plasma properties and the ion flux at electrodes located adjacent to the electron beam. A Langmuir probe is used to determine the plasma density and electron temperature, while an energy-resolving mass spectrometer is used to determine the ion energies and fluxes at electrodes. Together the diagnostics provide a comprehensive description of the system. These plasma parameters will be determined as a function of gas background, electron beam intensity, and electrode bias. This work was supported by the Office of Naval Research.