Diagnostics in a high-density plasma generated by a pulsed electron beam

Abstract

Summary form only given. At NRL, a 'Large Area Plasma Processing System' has been developed based on the high-energy electron beam (e-beam) ionization process, with the goal of modifying the surface properties of materials over large areas (/spl sim/1 square meter). The plasmas produced are high density (n/sub e/=10/sup 9/-10/sup 12/ cm/sup -3/) with low electron temperatures (T/sub e//spl ap/0.5 eV) and subsequently low plasma potentials at gas pressures of 10-150 mtorr. The plasmas well defined locally and temporally by the e-beam. In this presentation, temporally resolved measurements from Langmuir probes, microwave transmission, [energy resolved] ion mass spectrometry, and optical emission spectroscopy presented from plasmas formed by 2 keV e-beams operated for 1-6 milliseconds at 10-20% duty factors. Plasma parameters are correlated to e-beam energy and density measurements using a differentially pumped retarding field analyzer. A strong emphasis is placed on the experimental details of these measurements such as probe surface and chamber contamination, necessary support electronics, as well as the relevant physics associated with the wall or electrode placement in these low temperature high-density plasmas.