Density Measurements of Negative Hydrogen Ions Using Mass Spectrometer
Abstract
Measurement of negative ion density in a source plasma is necessary for optimizing the extraction of negative ion current. Bacal and co-workers proposed a method to measure the negative ion density by detaching the electron current due to the photodetachment of negative ions using a pulse laser (Bacal et al., 1979). This paper describes a method to determine the negative ion density in a plasma by a coupled mass analysis and Langmuir probe diagnosis of the plasma. The H- ion density was estimated from the relation equating the ratio of the negative ion and electron currents to the ratio of the ion and electron densities; I- / Ic = n- / nc. The proposed estimates consider the collection factor n- / nc.
Published
2012-07-03
Issue
Section
Articles
Submission of a manuscript implies: that the work described has not been published before (except in the form of an abstract or as part of a published lecture, review, or thesis); that it is not under consideration for publication elsewhere; that its publication has been approved by all co-authors, if any, as well as by the responsible authorities at the institute where the work has been carried out; that, if and when the manuscript is accepted for publication, the authors agree to the automatic transfer of the copyright to the publisher; that the manuscript will not be published elsewhere in any language without the consent of the copyright holders; that written permission of the copyright holder is obtained by the authors for material used from other copyrighted sources; and that any costs associated with obtaining this permission are the authors’ responsibility.
