An Apparatus for Electron Energy Analysis in Glow Discharge Plasmas

Abstract

An apparatus has been designed and built for the analysis of electron energies in low temperature glow discharge plasmas. The technique involves sampling the plasma via a molecular leak and energy analyzing the electrons by a retarding potential field. Integral retarding potential curves can be plotted directly on an X-Y recorder, or the integral signal can be differentiated electronically to yield a curve which is proportional to the electron energy distribution. The characteristics of the apparatus, including its resolving power, are discussed, and some preliminary results are described.

Space Simulation Testing of the Helicon Double Layer Thruster Prototype

“…RFEA probes can therefore yield informa tion about the plasma potential, Vp, the ion beam potential, Vj,, if present, and the plasma ion density, rij. Although various designs have been developed over several decades (Neiswender and Kohout, 1972;Hopman et al, 1977;Bohm and Perrin, 1993;Conway et al, 1998), not as many theoretical studies of RFEA probes have been undertaken compared to the num ber for Langmuir probes. Several studies have also compared the plasma properties determined with Langmuir probes and RFEAs and have found good agreement between the two diagnostics (Ingram and Braithwaite, 1988;Gahan et al, 2008).…”

Lock-in technique for precise measurement of ion distribution functions

“…The ion velocity distribution function (IVDF) is commonly measured by retarding field energy analyzers (RFEAs) [3][4][5][6][7][8][9][10][11][12][13][14]. The first theoretical and experimental investigations of the design and performance of such devices date back to the 1960s [15][16][17][18][19]. An RFEA generally consists of a set of electrically biased grids and a collector plate for the detection of the current of the incident ions.…”