Numerical Study of the Ripple Resonance Diffusion of Alpha Particles in Tokamaks

• MIMATA Hideyuki

  Tokyo Institute of Technology, Tokyo 152-8550, Japan

• TANI Keiji

  Nippon Advanced Technology Co., Ltd. Naka Office, Naka 311-0193, Japan

• TSUTSUI Hiroaki

  Tokyo Institute of Technology, Tokyo 152-8550, Japan

• TOBITA Kenji

  Japan Atomic Energy Agency, Naka 311-0193, Japan

• TSUJI-IIO Shunji

  Tokyo Institute of Technology, Tokyo 152-8550, Japan

• SHIMADA Ryuichi

  Tokyo Institute of Technology, Tokyo 152-8550, Japan

抄録

The energy dependence of the diffusion coefficients of α particles in rippled fields of tokamaks is numerically investigated with an orbit-following Monte Carlo code. The diffusion coefficients are enhanced around the ripple resonance energy while they are not so much enhanced in the neighborhood of it. Consequently, they have a local minimum near the resonance energy, and hence they have an M-shaped energy dependence. Ripple resonance is caused by a radial change of the toroidal precession of banana particles, and creates islands in (Nφ, ψ) phase space. Since particles outside the separatrix are the main contributors to diffusion enhancement, the M-shaped energy dependence is explained by the co-existence of open and closed orbits in the phase space. Ripple resonance diffusion is dominant for fusion-produced α particles since the resonance energy width occupies a large portion of the energy range in their slowing-down processes.

収録刊行物

• Plasma and Fusion Research

  Plasma and Fusion Research 4 008-008, 2009

  一般社団法人 プラズマ・核融合学会

キーワード

• α particle
• tokamak
• particle diffusion
• ripple resonance
• mapping model
• Poincaré map

詳細情報

• CRID: 1390282680229744000
• NII論文ID: 130000103681
• DOI: 10.1585/pfr.4.008
• ISSN: 18806821
• Web Site: http://www.jstage.jst.go.jp/article/pfr/4/0/4_0_008/_pdf
• 本文言語コード: en
• データソース種別:
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• 抄録ライセンスフラグ: 使用不可