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Title: Optimization of closed ion source for a high-sensitivity residual gas analyzer

Abstract

A closed ion source (CIS) has been optimized by investigating the effect of electron entrance slit size and the effect of mesh in the slit. A stainless steel mesh was placed on the electron entrance slits for a uniform potential distribution inside the CIS anode. Sensitivity of the closed ion sources having four different slit sizes with and without the mesh was compared using mass spectra of SF{sub 6} gas (97% He gas base) introduced into the CIS anode through a needle valve. For each CIS, isolation of anode potential with a mesh in the slit exhibited a significant sensitivity enhancement, but ion current measured directly behind each CIS showed negligible mesh effect. In order to elucidate the mesh effect, electron trajectories were simulated inside the anode. The computer simulation shows that, with mesh in the slit, more electrons are focused to a central region of the anode. This suggests ions generated in the CIS with mesh should have higher probability of passing through the quadrupole mass filter.

Authors:
; ;
Publication Date:
OSTI Identifier:
22258714
Resource Type:
Journal Article
Journal Name:
Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films
Additional Journal Information:
Journal Volume: 32; Journal Issue: 2; Other Information: (c) 2014 American Vacuum Society; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0734-2101
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ANODES; COMPARATIVE EVALUATIONS; COMPUTERIZED SIMULATION; ELECTRONS; FILTERS; ION SOURCES; IONS; MASS SPECTRA; OPTIMIZATION; SENSITIVITY; STAINLESS STEELS; SULFUR FLUORIDES; VALVES

Citation Formats

Han, Cheolsu, Rok Ahn, Jong, Jung Ahn, Sang, and Joon Park, Chang, E-mail: cjpark@kriss.re.kr. Optimization of closed ion source for a high-sensitivity residual gas analyzer. United States: N. p., 2014. Web. doi:10.1116/1.4835635.
Han, Cheolsu, Rok Ahn, Jong, Jung Ahn, Sang, & Joon Park, Chang, E-mail: cjpark@kriss.re.kr. Optimization of closed ion source for a high-sensitivity residual gas analyzer. United States. https://doi.org/10.1116/1.4835635
Han, Cheolsu, Rok Ahn, Jong, Jung Ahn, Sang, and Joon Park, Chang, E-mail: cjpark@kriss.re.kr. 2014. "Optimization of closed ion source for a high-sensitivity residual gas analyzer". United States. https://doi.org/10.1116/1.4835635.
@article{osti_22258714,
title = {Optimization of closed ion source for a high-sensitivity residual gas analyzer},
author = {Han, Cheolsu and Rok Ahn, Jong and Jung Ahn, Sang and Joon Park, Chang, E-mail: cjpark@kriss.re.kr},
abstractNote = {A closed ion source (CIS) has been optimized by investigating the effect of electron entrance slit size and the effect of mesh in the slit. A stainless steel mesh was placed on the electron entrance slits for a uniform potential distribution inside the CIS anode. Sensitivity of the closed ion sources having four different slit sizes with and without the mesh was compared using mass spectra of SF{sub 6} gas (97% He gas base) introduced into the CIS anode through a needle valve. For each CIS, isolation of anode potential with a mesh in the slit exhibited a significant sensitivity enhancement, but ion current measured directly behind each CIS showed negligible mesh effect. In order to elucidate the mesh effect, electron trajectories were simulated inside the anode. The computer simulation shows that, with mesh in the slit, more electrons are focused to a central region of the anode. This suggests ions generated in the CIS with mesh should have higher probability of passing through the quadrupole mass filter.},
doi = {10.1116/1.4835635},
url = {https://www.osti.gov/biblio/22258714}, journal = {Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films},
issn = {0734-2101},
number = 2,
volume = 32,
place = {United States},
year = {Sat Mar 15 00:00:00 EDT 2014},
month = {Sat Mar 15 00:00:00 EDT 2014}
}