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Title: Ion source with improved primary arc collimation

Abstract

An improved negative ion source is provided in which a self-biasing, molybdenum collimator is used to define the primary electron stream arc discharge from a filament operated at a negative potential. The collimator is located between the anode and the filament. It is electrically connected to the anode by means of an appropriate size resistor such that the collimator is biased at essentially the filament voltage during operation. Initially, the full arc voltage appears across the filament to collimator until the arc discharge strikes. Then the collimator biases itself to essentially filament potential due to current flow through the resistor thus defining the primary electron stream without intercepting any appreciable arc power. The collimator aperture is slightly smaller than the anode aperture to shield the anode from the arc power which, in the past, has caused overheating and erosion of the anode collimator during extended time pulsed-beam operation of the source. With the self-biasing collimator of this invention, the ion source may be operated from short pulse periods to steady-state without destroying the anode.

Inventors:
Issue Date:
OSTI Identifier:
6741810
Application Number:
ON: DE84014359
Assignee:
Dept. of Energy ERA-09-036489; EDB-84-122112
DOE Contract Number:  
AC05-84OS21400
Resource Type:
Patent
Resource Relation:
Other Information: Portions are illegible in microfiche products
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ELECTRON BEAM ION SOURCES; DESIGN; ANIONS; COLLIMATORS; ISOTOPE SEPARATION; CHARGED PARTICLES; ION SOURCES; IONS; SEPARATION PROCESSES 640301* -- Atomic, Molecular & Chemical Physics-- Beams & their Reactions

Citation Formats

Dagenhart, W.K. Ion source with improved primary arc collimation. United States: N. p., 1983. Web.
Dagenhart, W.K. Ion source with improved primary arc collimation. United States.
Dagenhart, W.K. Fri . "Ion source with improved primary arc collimation". United States.
@article{osti_6741810,
title = {Ion source with improved primary arc collimation},
author = {Dagenhart, W.K.},
abstractNote = {An improved negative ion source is provided in which a self-biasing, molybdenum collimator is used to define the primary electron stream arc discharge from a filament operated at a negative potential. The collimator is located between the anode and the filament. It is electrically connected to the anode by means of an appropriate size resistor such that the collimator is biased at essentially the filament voltage during operation. Initially, the full arc voltage appears across the filament to collimator until the arc discharge strikes. Then the collimator biases itself to essentially filament potential due to current flow through the resistor thus defining the primary electron stream without intercepting any appreciable arc power. The collimator aperture is slightly smaller than the anode aperture to shield the anode from the arc power which, in the past, has caused overheating and erosion of the anode collimator during extended time pulsed-beam operation of the source. With the self-biasing collimator of this invention, the ion source may be operated from short pulse periods to steady-state without destroying the anode.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1983},
month = {12}
}