Uniform H(-) ion beam extraction in a large negative ion source with a tent-shaped magnetic filter.
Rev Sci Instrum
; 79(2 Pt 2): 02C111, 2008 Feb.
Article
em En
| MEDLINE
| ID: mdl-18315237
ABSTRACT
Based on previous studies on the spatial uniformity of the negative ion beam, the external magnetic filter was replaced to a novel tent-shaped magnetic filter in the JAEA 10 A negative ion source. The line-cusp field configuration on the source chamber was also changed to form a symmetric magnetic field like many of positive ion sources aiming at high proton yield. This magnetic field configuration allows fast electrons emitted from filament cathodes to rotate azimuthally inside the source chamber. The source configuration thus prevents localization of fast electrons due to their B x grad B drift in the filter field. As a result, the H(-) ion beam profile extracted from a wide region of 340 x 170 mm(2) showed reduction of standard deviation from 16% in the original to 7.9% with the tent filter. The negative ion source with the tent filter satisfied the requirement of the beam uniformity for a large negative ion source in the ITER neutral beam injection.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Rev Sci Instrum
Ano de publicação:
2008
Tipo de documento:
Article
País de afiliação:
Japão