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Negative Ion Collisions Electronic Desorption Experiments Study

Posted on:2011-08-12Degree:MasterType:Thesis
Country:ChinaCandidate:J ZhaoFull Text:PDF
GTID:2190360305998658Subject:Atomic and molecular physics
Abstract/Summary:PDF Full Text Request
Electron detachment research on negative-ions in collision with atom or molec-ular can provide essential experimental data for electron correlation theory and have a great influence on the astrophysics, plasma physics, earth ionosphere physics. The main work of this thesis is build a new detection system and single electron detachment cross section measurement of negative-ions in collision with atom.I. We made great improvement on the detection system of the electron detach-ment measurement system. The MCP delay-line anode position sensitive detector was introduced to detect ions and neutrals. The operating parameters of MCP are investigated thoroughly, and we present the dependence of the pulse height distributions (PHD) of the anode signals on MCP bias voltage, incident beam en-ergy, incident beam intensity, and incident ion species. The optimum parameters, such as bias voltage of the MCP, the threshold of the electronics and incident ions intensity, are determined. The saturation curve of MCP and relative detection efficiency is also shown.II.We measured the single electron detachment cross sections of H-,C- in collision with N2 using the new position sensitive detection system. Consistency with other available experiment results shows the reliability of the new detection system. Then we measured single electron detachment cross section of 5-30keV Cu-,Ag-,Au-in collision with Ar and made detail analysis.
Keywords/Search Tags:negative ions, electron detachment cross section, MCP, delay-line anode position sensitive detector, PHD, count saturation curve, relative detection efficiency
PDF Full Text Request
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