Characteristics of an He⁺ beam extracted from a compact multicusp ion source

Authors

Masaki Nishiura ⋅ JP National Institute for Fusion Science, Toki, Japan
Mamiko Sasao ⋅ JP National Institute for Fusion Science, Toki, Japan
Motoi Wada ⋅ JP Faculty of Engineering, Doshisha University, Japan
Makoto Hamabe ⋅ JP Chubu University, Japan
Tsutomu Kuroda ⋅ JP Chubu University, Japan
Samar K. Guharay ⋅ US Institute for Plasma Research, University of Maryland, USA
Henry J. Ramos ⋅ PH National Institute of Physics, University of the Philippines Diliman

Abstract

When an ion beam is extracted from plasma, the beam size expands both by the space charge and the beam emittance. The space charge, however, can be neutralized by oppositely charged particles, which are produced through the beam-induced ionization process of the residual gas. Those effects are especially important when the beam current density is high and the extraction voltage is low (<10 kV).
A prototype compact multicusp He⁺ ion source has been developed to produce a He⁺ beam for the purpose of the alpha particle diagnostics of a nuclear fusion device. Since the optimum beam energy for the conversion from He⁺ to He^- in alkali vapor is about 10 keV, the transport of the intense low energy He⁺ beam is essential for the development. We have measured the He⁺ beam current, the emittance and plasma parameters of the ion source. In the present work, the correlation among these parameters and the prospect to realize this diagnostic system are discussed.

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Issue

1999: Proceedings of the 17th National Physics Congress of the Samahang Pisika ng Pilipinas

Article ID

SPP-1999-SP-15

Section

Spectroscopy and Interferometry

Published

1999-10-22

How to Cite

[1]

M Nishiura, M Sasao, M Wada, M Hamabe, T Kuroda, SK Guharay, and HJ Ramos, Characteristics of an He+ beam extracted from a compact multicusp ion source, Proceedings of the Samahang Pisika ng Pilipinas 17, SPP-1999-SP-15 (1999). URL: https://proceedings.spp-online.org/article/view/SPP-1999-SP-15.