2015 Fiscal Year Final Research Report

Quantitative evaluation of high Z impurity screening effect in a stochastic magnetic layer and transport model validation

Research Project

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Project/Area Number	25420893
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Research Field	Nuclear fusion studies
Research Institution	National Institute for Fusion Science
Principal Investigator	Kobayashi Masahiro 核融合科学研究所, ヘリカル研究部, 准教授 (30399307)
Co-Investigator(Renkei-kenkyūsha)	MORITA Shigeru 核融合科学研究所, ヘリカル研究部, 教授 (80174423) GOTO Motoshi 核融合科学研究所, ヘリカル研究部, 准教授 (00290916) KAWAMURA Gakushi 核融合科学研究所, ヘリカル研究部, 助教 (70509520) DAI Shuyu 核融合科学研究所, ヘリカル研究部, 特任研究員 (50754686)
Research Collaborator	FENG Yuehe マックスプランク研究所, 上級研究員 Xu Yuhong 西南物理研究所, 西南物理研究所, 教授 Dong Chunfeng 西南物理研究所, 准教授 SCHMITZ Oliver ウィスコンシン大学, 准教授 CORRE Yann カダラッシュ研究所
Project Period (FY)	2013-04-01 – 2016-03-31
Keywords	核融合 / ストキャスティック磁場 / 不純物輸送 / 分光計測 / 数値シミュレーション
Outline of Final Research Achievements	Transport properties of high Z (high atomic number) impurity in the edge stochastic magnetic layer have been investigated. Following results are obtained: Screening effects have been observed for different impurity species of Z numbers, Z=2, 6 and 26 (helium, carbon and iron). The current transport model needs a cross-field transport coefficient for impurity larger than the background plasma by a factor of 3 to 4. About 10% of first wall source should be considered to interpret the experimental results. Multi-machine comparison shows that the stochastic layer width should be larger than the impurity penetration length by a factor of 10 in order to realize effective impurity screening. Impurity flow velocity parallel to the magnetic field lines has been successfully measured, in which a clear correlation between the flow field and magnetic structure is identified. The result opens further possibility of detailed validation of the current transport model in future.
Free Research Field	磁場閉じ込め核融合装置の周辺プラズマ輸送