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Title: Simulations of the response function of a plasma ion beam spectrometer for the Cassini mission to Saturn

Abstract

To obtain very high ({approx}1%) energy resolution with spherical-section electrostatic analyzers requires high precision in both fabrication and in the alignment process. In order to aid in the calibration of the instrument and to help minimize fabrication costs, we have applied simulation models to the ion beam spectrometer for the NASA/ESA Cassini mission to Saturn. Previously we studied the effects of misalignment and simple irregularities of the hemispherical surfaces on the performance of an electrostatic analyzer. We have considered a hemispherical electrostatic analyzer equipped with an aperture plate to collimate the stray electric field at the entrance apertures. The influence of a curved entrance aperture has also been added to the simulation model, and its effects have been studied in detail. A cylindrical three-dimensional simultaneous overrelaxation algorithm has been introduced to solve for the stray electric field. The maximum loss of transmitted particles with respect to the transmission of an ideal instrument has been set at 10{percent}. We demonstrate that the deviation in the distributions of the energies is less than 0.2{percent} and that the deviation in the distributions of entrance angles of transmitted particles is less than 0.1{degree}. It has been found that the energy resolution of an electrostaticmore » analyzer can be improved from {Delta}{ital E}/{ital E}=(1.6{plus_minus}0.2){percent} to {Delta}{ital E}/{ital E}=(1.3{plus_minus}0.2){percent} by the introduction of front aperture plates. Through the introduction of curved entrance slits, the azimuthal angle resolution has changed from {beta}=(1.4{plus_minus}0.1){degree} for the simplified geometry simulation results of our previous article to {beta}=(2.3{plus_minus}0.1){degree}. We have confirmed that an accuracy of 25 {mu}m in the alignment of the two hemispherical surfaces is sufficient to give the instrument the desired resolutions. {copyright} {ital 1996 American Institute of Physics.}« less

Authors:
;  [1];  [2];  [3]
  1. Department of Physics, University of Oulu, Oulu, FIN-90570 (Finland)
  2. Automation and Space Technology, VTT Technical Research Centre of Finland, P.O. Box 1303, FIN-02044 Espoo (Finland)
  3. Space and Atmospheric Sciences Group, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
Publication Date:
OSTI Identifier:
283558
Resource Type:
Journal Article
Journal Name:
Review of Scientific Instruments
Additional Journal Information:
Journal Volume: 67; Journal Issue: 4; Other Information: PBD: Apr 1996
Country of Publication:
United States
Language:
English
Subject:
44 INSTRUMENTATION, INCLUDING NUCLEAR AND PARTICLE DETECTORS; SPACE FLIGHT; ELECTROSTATIC SPECTROMETERS; RESPONSE FUNCTIONS; INTERPLANETARY SPACE; SATURN PLANET; ELECTROSTATIC ANALYZERS; ENERGY RESOLUTION; ION BEAMS; BEAM OPTICS; COMPUTERIZED SIMULATION

Citation Formats

Vilppola, J H, Tanskanen, P J, Huomo, H, and Barraclough, B L. Simulations of the response function of a plasma ion beam spectrometer for the Cassini mission to Saturn. United States: N. p., 1996. Web. doi:10.1063/1.1146881.
Vilppola, J H, Tanskanen, P J, Huomo, H, & Barraclough, B L. Simulations of the response function of a plasma ion beam spectrometer for the Cassini mission to Saturn. United States. https://doi.org/10.1063/1.1146881
Vilppola, J H, Tanskanen, P J, Huomo, H, and Barraclough, B L. 1996. "Simulations of the response function of a plasma ion beam spectrometer for the Cassini mission to Saturn". United States. https://doi.org/10.1063/1.1146881.
@article{osti_283558,
title = {Simulations of the response function of a plasma ion beam spectrometer for the Cassini mission to Saturn},
author = {Vilppola, J H and Tanskanen, P J and Huomo, H and Barraclough, B L},
abstractNote = {To obtain very high ({approx}1%) energy resolution with spherical-section electrostatic analyzers requires high precision in both fabrication and in the alignment process. In order to aid in the calibration of the instrument and to help minimize fabrication costs, we have applied simulation models to the ion beam spectrometer for the NASA/ESA Cassini mission to Saturn. Previously we studied the effects of misalignment and simple irregularities of the hemispherical surfaces on the performance of an electrostatic analyzer. We have considered a hemispherical electrostatic analyzer equipped with an aperture plate to collimate the stray electric field at the entrance apertures. The influence of a curved entrance aperture has also been added to the simulation model, and its effects have been studied in detail. A cylindrical three-dimensional simultaneous overrelaxation algorithm has been introduced to solve for the stray electric field. The maximum loss of transmitted particles with respect to the transmission of an ideal instrument has been set at 10{percent}. We demonstrate that the deviation in the distributions of the energies is less than 0.2{percent} and that the deviation in the distributions of entrance angles of transmitted particles is less than 0.1{degree}. It has been found that the energy resolution of an electrostatic analyzer can be improved from {Delta}{ital E}/{ital E}=(1.6{plus_minus}0.2){percent} to {Delta}{ital E}/{ital E}=(1.3{plus_minus}0.2){percent} by the introduction of front aperture plates. Through the introduction of curved entrance slits, the azimuthal angle resolution has changed from {beta}=(1.4{plus_minus}0.1){degree} for the simplified geometry simulation results of our previous article to {beta}=(2.3{plus_minus}0.1){degree}. We have confirmed that an accuracy of 25 {mu}m in the alignment of the two hemispherical surfaces is sufficient to give the instrument the desired resolutions. {copyright} {ital 1996 American Institute of Physics.}},
doi = {10.1063/1.1146881},
url = {https://www.osti.gov/biblio/283558}, journal = {Review of Scientific Instruments},
number = 4,
volume = 67,
place = {United States},
year = {Mon Apr 01 00:00:00 EST 1996},
month = {Mon Apr 01 00:00:00 EST 1996}
}