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Title: Electrostatic energy analyzer measurements of low energy zirconium beam parameters in a plasma sputter-type negative ion source

Abstract

A plasma sputter-type negative ion source is utilized to produce and detect negative Zr ions with energies between 150 and 450 eV via a retarding potential-type electrostatic energy analyzer. Traditional and modified semi-cylindrical Faraday cups (FC) inside the analyzer are employed to sample negative Zr ions and measure corresponding ion currents. The traditional FC registered indistinct ion current readings which are attributed to backscattering of ions and secondary electron emissions. The modified Faraday cup with biased repeller guard ring, cut out these signal distortions leaving only ringings as issues which are theoretically compensated by fitting a sigmoidal function into the data. The mean energy and energy spread are calculated using the ion current versus retarding potential data while the beam width values are determined from the data of the transverse measurement of ion current. The most energetic negative Zr ions yield tighter energy spread at 4.11 eV compared to the least energetic negative Zr ions at 4.79 eV. The smallest calculated beam width is 1.04 cm for the negative Zr ions with the highest mean energy indicating a more focused beam in contrast to the less energetic negative Zr ions due to space charge forces.

Authors:
 [1];  [2]; ; ;  [1]
  1. Plasma Physics Laboratory, National Institute of Physics, University of the Philippines, Diliman, Quezon City 1101 (Philippines)
  2. (Philippines)
Publication Date:
OSTI Identifier:
22085915
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 83; Journal Issue: 2; Conference: ICIS 2011: 14. international conference on ion sources, Giardini-Naxos, Sicily (Italy), 12-16 Sep 2011; Other Information: (c) 2012 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ANIONS; BACKSCATTERING; BEAM PROFILES; CURRENTS; CYLINDRICAL CONFIGURATION; ELECTRON EMISSION; EV RANGE; FARADAY CUPS; ION BEAMS; ION SOURCES; PLASMA; SIGNAL DISTORTION; SPACE CHARGE; SPUTTERING; ZIRCONIUM IONS

Citation Formats

Malapit, Giovanni M., Department of Physical Sciences, University of the Philippines Baguio, Baguio City 2600, Mahinay, Christian Lorenz S., Poral, Matthew D., and Ramos, Henry J. Electrostatic energy analyzer measurements of low energy zirconium beam parameters in a plasma sputter-type negative ion source. United States: N. p., 2012. Web. doi:10.1063/1.3665966.
Malapit, Giovanni M., Department of Physical Sciences, University of the Philippines Baguio, Baguio City 2600, Mahinay, Christian Lorenz S., Poral, Matthew D., & Ramos, Henry J. Electrostatic energy analyzer measurements of low energy zirconium beam parameters in a plasma sputter-type negative ion source. United States. doi:10.1063/1.3665966.
Malapit, Giovanni M., Department of Physical Sciences, University of the Philippines Baguio, Baguio City 2600, Mahinay, Christian Lorenz S., Poral, Matthew D., and Ramos, Henry J. 2012. "Electrostatic energy analyzer measurements of low energy zirconium beam parameters in a plasma sputter-type negative ion source". United States. doi:10.1063/1.3665966.
@article{osti_22085915,
title = {Electrostatic energy analyzer measurements of low energy zirconium beam parameters in a plasma sputter-type negative ion source},
author = {Malapit, Giovanni M. and Department of Physical Sciences, University of the Philippines Baguio, Baguio City 2600 and Mahinay, Christian Lorenz S. and Poral, Matthew D. and Ramos, Henry J.},
abstractNote = {A plasma sputter-type negative ion source is utilized to produce and detect negative Zr ions with energies between 150 and 450 eV via a retarding potential-type electrostatic energy analyzer. Traditional and modified semi-cylindrical Faraday cups (FC) inside the analyzer are employed to sample negative Zr ions and measure corresponding ion currents. The traditional FC registered indistinct ion current readings which are attributed to backscattering of ions and secondary electron emissions. The modified Faraday cup with biased repeller guard ring, cut out these signal distortions leaving only ringings as issues which are theoretically compensated by fitting a sigmoidal function into the data. The mean energy and energy spread are calculated using the ion current versus retarding potential data while the beam width values are determined from the data of the transverse measurement of ion current. The most energetic negative Zr ions yield tighter energy spread at 4.11 eV compared to the least energetic negative Zr ions at 4.79 eV. The smallest calculated beam width is 1.04 cm for the negative Zr ions with the highest mean energy indicating a more focused beam in contrast to the less energetic negative Zr ions due to space charge forces.},
doi = {10.1063/1.3665966},
journal = {Review of Scientific Instruments},
number = 2,
volume = 83,
place = {United States},
year = 2012,
month = 2
}
  • The energy distribution of ion beams is important especially for low energy ion beam applications. The energy distributions of negative-ion beams produced through secondary ion emission by sputtering were measured and compared with theoretically estimated distributions by use of four different negative-ion production probability equations (modified surface ionization model, exponential velocity dependence model, and our modified exponential velocity dependence models (modified decaying factor model and combination model of velocity dependence and surface ionization)). In the measurements, the energy distributions of C{sup {minus}} and Ag{sup {minus}} beams had a peak at a few to several eV and the full width atmore » half maximum were 15 eV and 11 eV, respectively. These results could be well explained by the estimated distributions by virtue of our combination model or the modified surface ionization model. {copyright} {ital 1996 American Institute of Physics.}« less
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