Development of a radio frequency ion source with multi-helicon plasma injectors for neutral beam injection system of Versatile Experiment Spherical Torus

Journal Article · Sat Feb 15 04:00:00 EST 2014 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.4852276· OSTI ID:22253666

Choe, Kyumin; Jung, Bongki ^[1]; Chung, Kyoung-Jae ^[2]; Hwang, Y. S. ^[1]

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1. Department of Nuclear Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of)
2. Center for Advance Research in Fusion Reactor Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of)

Despite of high plasma density, helicon plasma has not yet been applied to a large area ion source such as a driver for neutral beam injection (NBI) system due to intrinsically poor plasma uniformity in the discharge region. In this study, a radio-frequency (RF) ion source with multi-helicon plasma injectors for high plasma density with good uniformity has been designed and constructed for the NBI system of Versatile Experiment Spherical Torus at Seoul National University. The ion source consists of a rectangular plasma expansion chamber (120 × 120 × 120 mm{sup 3}), four helicon plasma injectors with annular permanent magnets and RF power system. Main feature of the source is downstream plasma confinement in the cusp magnetic field configuration which is generated by arranging polarities of permanent magnets in the helicon plasma injectors. In this paper, detailed design of the multi-helicon plasma injector and plasma characteristics of the ion source are presented.

• OSTI ID: 22253666
• Journal Information: Review of Scientific Instruments, Journal Name: Review of Scientific Instruments Journal Issue: 2 Vol. 85; ISSN 0034-6748; ISSN RSINAK
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
BEAM INJECTION
CUSPED GEOMETRIES
ION SOURCES
PERMANENT MAGNETS
PLASMA CONFINEMENT
PLASMA DENSITY
PLASMA EXPANSION
POWER SYSTEMS
RADIOWAVE RADIATION
SPHERICAL CONFIGURATION