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Title: Negative ion source

Abstract

An ionization vessel is divided into an ionizing zone and an extraction zone by a magnetic filter. The magnetic filter prevents high-energy electrons from crossing from the ionizing zone to the extraction zone. A small positive voltage impressed on a plasma grid, located adjacent an extraction grid, positively biases the plasma in the extraction zone to thereby prevent positive ions from migrating from the ionizing zone to the extraction zone. Low-energy electrons, which would ordinarily be dragged by the positive ions into the extraction zone, are thereby prevented from being present in the extraction zone and being extracted along with negative ions by the extraction grid. Additional electrons are suppressed from the output flux using ExB drift provided by permanent magnets and the extractor grid electrical field.

Inventors:
 [1];  [2]
  1. (Hercules, CA)
  2. (Alamo, CA)
Issue Date:
Research Org.:
Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA
OSTI Identifier:
865274
Patent Number(s):
4486665
Assignee:
United States of America as represented by United States (Washington, DC) LBNL
DOE Contract Number:  
AC03-76SF00098
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
negative; source; ionization; vessel; divided; ionizing; zone; extraction; magnetic; filter; prevents; high-energy; electrons; crossing; positive; voltage; impressed; plasma; grid; located; adjacent; positively; biases; prevent; migrating; low-energy; ordinarily; dragged; prevented; extracted; additional; suppressed; output; flux; exb; drift; provided; permanent; magnets; extractor; electrical; field; magnetic filter; electrical field; energy electrons; permanent magnet; permanent magnets; located adjacent; energy electron; extraction zone; additional electrons; extraction grid; filter prevents; positive voltage; ionizing zone; high-energy electron; high-energy electrons; /250/376/

Citation Formats

Leung, Ka-Ngo, and Ehlers, Kenneth W. Negative ion source. United States: N. p., 1984. Web.
Leung, Ka-Ngo, & Ehlers, Kenneth W. Negative ion source. United States.
Leung, Ka-Ngo, and Ehlers, Kenneth W. Sun . "Negative ion source". United States. https://www.osti.gov/servlets/purl/865274.
@article{osti_865274,
title = {Negative ion source},
author = {Leung, Ka-Ngo and Ehlers, Kenneth W.},
abstractNote = {An ionization vessel is divided into an ionizing zone and an extraction zone by a magnetic filter. The magnetic filter prevents high-energy electrons from crossing from the ionizing zone to the extraction zone. A small positive voltage impressed on a plasma grid, located adjacent an extraction grid, positively biases the plasma in the extraction zone to thereby prevent positive ions from migrating from the ionizing zone to the extraction zone. Low-energy electrons, which would ordinarily be dragged by the positive ions into the extraction zone, are thereby prevented from being present in the extraction zone and being extracted along with negative ions by the extraction grid. Additional electrons are suppressed from the output flux using ExB drift provided by permanent magnets and the extractor grid electrical field.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1984},
month = {1}
}

Patent:

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