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Updated: Jul 7, 2026
07:17
Non-equilibrium Microwave Plasma for Efficient High Temperature Chemistry
Published on: August 1, 2017
Negative ion production in cesium seeded high electron temperature plasmas
1Japan Atomic Energy Agency (JAEA), Fusion Research and Development Directorate, Naka, Japan. inoue.takashi52@jaea.go.jp
The Review of Scientific Instruments
|March 5, 2008
Summary
Cesium seeding in negative ion sources enhances H(-) ion beam intensity locally where electron temperature is high. This suggests high electron temperatures benefit negative ion surface production.
Area of Science:
- Plasma Physics
- Ion Source Technology
Background:
- Steep gradients in electron temperature and H(-) ion beam intensity observed in large negative ion sources.
- Cesium seeding's effect on these gradients was investigated for uniformity improvement.
Purpose of the Study:
- To investigate the impact of cesium seeding on H(-) ion beam intensity and electron temperature profiles.
- To understand the relationship between electron temperature and H(-) ion beam intensity under cesium-seeded conditions.
Main Methods:
- Experiments conducted on a large negative ion source.
- Observation of electron temperature and H(-) ion beam intensity profiles.
- Introduction of cesium (Cs) into the ion source.
Main Results:
- Cesium seeding altered the H(-) ion beam intensity gradient.
- Electron temperature distribution remained unaffected by cesium.
- H(-) ion beam intensity was enhanced locally in areas with high electron temperature plasmas under Cs-seeded conditions.
Conclusions:
- High electron temperature plasmas appear advantageous for negative ion surface production.
- Enhanced dissociation yielding proton or atoms as parent particles is a likely mechanism.
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