Electrostatic Energy Analyzer (ESA)
An electrostatic probe that determines fraction of multiply charged ions and ion energy distribution.
Figure 1. Simulation results showing the dispersion of ions with different energy to charge ratios within the ESA. (from ref. 3).
Figure 2. The parallel-plate energy analyzer (large box with narrow entrance slit) installed in the LVTF along with (from left to right) the RPA, the gridded Faraday probe, and the nude Faraday probe. (from ref. 3).
An ESA has been developed at PEPL.
The ESA uses two instruments to conduct its measurements: a 45-degree, Parallel-Plate Energy Analyzer and a TOF.
The parallel plate section of the ESA acts as a velocity per charge filter for a given ion species since only ions of a specific energy-to-charge ratio are collected.
An extension has been machined to allow this device to be used as a time of flight mass spectrometer.
The mass to charge ratios of plume ions can be determined by using the fact that ions of different charge but equal mass are accelerated to different velocities by a given potential drop.
The fraction of multiply charged ions can be determined.
Figure 3. CAD model views of an ESA developed at PEPL.
Selected Relevant Publications
Beal, B. E., and Gallimore, A. D., "Energy Analysis of a Hall Thruster Cluster,"
IEPC-2003-035, 29th International Electric Propulsion Conference, Toulouse, France, March 17-20, 2003.
Beal, B. E., "Clustering of Hall Effect Thrusters for High-Power Electric Propulsion Applications,"
Ph.D. Dissertation, University of Michigan, 2004.