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Title: Beam deflection by plasma grid filter current in the negative-ion source for JT-60U neutral beam injection system

Abstract

In the JT-60U negative-ion-based neutral beam injection system, the effect of negative ion and electron deflection by the plasma grid (PG) magnetic filter was studied. After a long-pulse operation of up to 19 s, a local melting was observed on the beamline near the ion source, facing the electron drift side of the PG magnetic field. It is confirmed that the experimental deflection of the negative-ion beam agrees well with the three-dimensional beam simulation result by taking account of the measured magnetic field. By using the code, it is found that some stripped electrons produced in the first acceleration gap pass through the down pitch of the multiple apertures in the next stage of acceleration grids, and then collide on the beamline around the melted location.

Authors:
; ; ; ; ; ; ; ;  [1]
  1. Naka Fusion Institute, Japan Atomic Energy Agency, 801-1 Mukouyama, Naka-shi, Ibaraki-ken 311-0193 (Japan)
Publication Date:
OSTI Identifier:
20779014
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 77; Journal Issue: 3; Conference: 11. international conference on ion sources, Caen (France), 12-16 Sep 2005; Other Information: DOI: 10.1063/1.2170088; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; ACCELERATION; ANIONS; APERTURES; BEAM DYNAMICS; COMPUTERIZED SIMULATION; CURRENTS; ELECTRON DRIFT; ELECTRONS; HEATING; ION BEAMS; ION SOURCES; JT-60U TOKAMAK; MAGNETIC FIELDS; MAGNETIC FILTERS; MELTING; PLASMA; PLASMA BEAM INJECTION; PULSES; THREE-DIMENSIONAL CALCULATIONS

Citation Formats

Umeda, N., Ikeda, Y., Hanada, M., Inoue, T., Kawai, M., Kazawa, M., Komata, M., Mogaki, K., and Ohga, T. Beam deflection by plasma grid filter current in the negative-ion source for JT-60U neutral beam injection system. United States: N. p., 2006. Web. doi:10.1063/1.2170088.
Umeda, N., Ikeda, Y., Hanada, M., Inoue, T., Kawai, M., Kazawa, M., Komata, M., Mogaki, K., & Ohga, T. Beam deflection by plasma grid filter current in the negative-ion source for JT-60U neutral beam injection system. United States. doi:10.1063/1.2170088.
Umeda, N., Ikeda, Y., Hanada, M., Inoue, T., Kawai, M., Kazawa, M., Komata, M., Mogaki, K., and Ohga, T. Wed . "Beam deflection by plasma grid filter current in the negative-ion source for JT-60U neutral beam injection system". United States. doi:10.1063/1.2170088.
@article{osti_20779014,
title = {Beam deflection by plasma grid filter current in the negative-ion source for JT-60U neutral beam injection system},
author = {Umeda, N. and Ikeda, Y. and Hanada, M. and Inoue, T. and Kawai, M. and Kazawa, M. and Komata, M. and Mogaki, K. and Ohga, T.},
abstractNote = {In the JT-60U negative-ion-based neutral beam injection system, the effect of negative ion and electron deflection by the plasma grid (PG) magnetic filter was studied. After a long-pulse operation of up to 19 s, a local melting was observed on the beamline near the ion source, facing the electron drift side of the PG magnetic field. It is confirmed that the experimental deflection of the negative-ion beam agrees well with the three-dimensional beam simulation result by taking account of the measured magnetic field. By using the code, it is found that some stripped electrons produced in the first acceleration gap pass through the down pitch of the multiple apertures in the next stage of acceleration grids, and then collide on the beamline around the melted location.},
doi = {10.1063/1.2170088},
journal = {Review of Scientific Instruments},
number = 3,
volume = 77,
place = {United States},
year = {Wed Mar 15 00:00:00 EST 2006},
month = {Wed Mar 15 00:00:00 EST 2006}
}