Optimization of the extraction of H- ions in a magnetized sheet plasma

Authors

  • Jose Karl Charles D. Sanchez National Institute of Physics, University of the Philippines Diliman
  • Henry J. Ramos National Institute of Physics, University of the Philippines Diliman

Abstract

A mass spectrometer is upgraded to compare the current intensity of the extracted H- ions to the current intensity of the electrons straying and entering the aperture of the spectrometer. The negative ion source used in these experiments have been described in reference 1. A 180°-deflection mass spectrometer is used. Dependence of the H- current on the bias to the plasma, electrode has been determined. Similarly the dependence of the H- current on the mass spectrometer coil current was obtained. The electron current detected by tire mass spectrometer as a function of the B-field intensity is shown. This is done to obtain the ratio of the currents of the extracted H- ions and the extracted electrons and thus obtain the ratio of the ion density to the electron density. Finally, the negative hydrogen ion to electron density ratio as a function of the bias to the plasma electrode for different field intensities were obtained. The ratio n-/ne, obtained was higher than results obtained from similar sources. A maximum H- ion current is obtained when the mass spectrometer B-field is 691 G and when the bias to the plasma electrode is near the value of the plasma floating potential.

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Article ID

SPP-1994-PL-02

Section

Plasma Physics and Liquid Crystals

Published

1994-10-15

How to Cite

[1]
JKCD Sanchez and HJ Ramos, Optimization of the extraction of H- ions in a magnetized sheet plasma, Proceedings of the Samahang Pisika ng Pilipinas 12, SPP-1994-PL-02 (1994). URL: https://proceedings.spp-online.org/article/view/SPP-1994-PL-02.