Production of high-current large-area negative hydrogen ion beams by a bucket-type ion source equipped with a magnetic filter

Conference · Tue Dec 31 04:00:00 EST 1996

OSTI ID:428024

Tanaka, M; Kawakami, H ^[1]; Takeiri, Y; Asano, E; Kaneko, O; Kuroda, T ^[2]

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1. Hitachi Ltd., Ibaraki (Japan)
2. National Inst. for Fusion Science, Nagoya, Aichi (Japan)

Magnetic multicusp ion sources, also known as bucket-type sources, are suitable for producing large-area ion beams and they have been developed as high-current ion sources in neutral beam injector (NBI) systems for nuclear fusion plasma heating. neutral beams are produced by neutralization of ion beams in the systems. Recently, development of a negative-ion-based NBI system has become desirable for higher energy neutral beam production. The neutralization efficiency of a positive ion beam decreases as beam energy rises. However, the neutralization efficiency of a negative ion beam is more than 60% at high energy (> 100 keV). The Large Helical Device (LHD) is under construction at National Institute for Fusion Science (NIFS). A negative-ion-based NBI system is planned to provide plasma heating of the LHD. In this research, the authors developed a large-area negative ion source, which is 1/3 the scale of the ion source planned for the LHD NBI. High-current H{sup {minus}} beam production (> 15 A: 1/3 current of LHD ion source) was a condition of the design.

• OSTI ID: 428024
• Report Number(s): CONF-960634--
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
BEAM INJECTION HEATING
BEAM NEUTRALIZATION
BEAM PRODUCTION
DESIGN
HELIOTRON
HYDROGEN IONS 1 MINUS
ION SOURCES
NEUTRAL ATOM BEAM INJECTION