Meniscus and beam halo formation in a tandem-type negative ion source with surface production

Journal Article · Mon Jun 04 00:00:00 EDT 2012 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4726262· OSTI ID:22025591

Miyamoto, K ^[1]; Okuda, S; Hatayama, A ^[2]

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1. Naruto University of Education, 748 Nakashima, Takashima, Naruto-cho, Naruto-shi, Tokushima 772-8502 (Japan)
2. Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522 (Japan)

A meniscus of plasma-beam boundary in H{sup -} ion sources largely affects the extracted H{sup -} ion beam optics. Although it is hypothesized that the shape of the meniscus is one of the main reasons for the beam halo observed in experiments, a physical mechanism of the beam halo formation is not yet fully understood. In this letter, it is first shown by the 2D particle in cell simulation that the H{sup -} ions extracted from the periphery of the meniscus cause a beam halo since the surface produced H{sup -} ions penetrate into the bulk plasma, and, thus, the resultant meniscus has a relatively large curvature.

• OSTI ID: 22025591
• Journal Information: Applied Physics Letters, Vol. 100, Issue 23; Other Information: (c) 2012 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
BEAM OPTICS
BEAM PROFILES
BEAM-PLASMA SYSTEMS
COMPUTERIZED SIMULATION
HYDROGEN IONS 1 MINUS
ION BEAMS
ION SOURCES
PLASMA
SURFACES
TWO-DIMENSIONAL CALCULATIONS