Improved production of N{sup +} ions from a multicusp ion beam apparatus
This invention is comprised of a method of generating a high purity (at least 98%) N{sup +} ion beam using a multicusp ion source having a chamber formed by a cylindrical chamber wall surrounded by a plurality of magnets, a filament centrally disposed in said chamber, a plasma electrode having an extraction orifice at one end of the chamber, a magnetic filter having two parallel magnets spaced from said plasma electrode and dividing the chamber into arc discharge and extraction regions. The method includes ionizing nitrogen gas in the arc discharge region of the chamber, maintaining the chamber wall at a positive voltage relative to the filament and at a magnitude for an optimum percentage of N{sup +} ions in the extracted ion beam, disposing a hot liner within the chamber and near the chamber wall to limit recombination of N{sup +} ions into the N{sub 2}{sup +} ions, spacing the magnets of the magnetic filter from each other for optimum percentage of N{sup +} ions in the extracted ion beams, and maintaining a relatively low pressure downstream of the extraction orifice and of a magnitude (preferably within the range of 3--8 {times} 10{sup {minus}4} torr) for an optimum percentage of N{sup +} ions in the extracted ion beam.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC03-76SF00098
- Assignee:
- Dept. of Energy
- Patent Number(s):
- PATENTS-US-A7774912
- Application Number:
- ON: DE94003044; PAN: 7-774,912
- OSTI ID:
- 140151
- Resource Relation:
- Other Information: PBD: 1991
- Country of Publication:
- United States
- Language:
- English
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