%0 Journal Article %T Study of particle behaviour at the edge in HT-7 tokamak %A Xu Wei %A Wan Bao-Nian %A Zhou Qian %A Wu Zhen-Wei %A Mao Jiao-Shan %A Li Jian-Gang %A
徐伟 %A 万宝年 %A 周倩 %A 吴振伟 %A 毛剑珊 %A 李建刚 %J 中国物理 B %D 2004 %I %X The cross-field diffusion coefficient (D_⊥) at the edge in the HT-7 tokamak is close to the Bohm value when the line average electron density ranges from 1.5×10^{19} to 3.0×10^{19}m^{-3}. The energy profile of the particles is derived directly from the H_α(D_α) line shape; the dissociative excitation of molecules is dominating when the local electron temperature is above 10eV. By means of the Monte Carlo method the D_α line shape is also simulated. We find that the molecular dissociation contributes to 57% of neutral atoms and 53% of emission intensity in front of the limiter, and 85% of neutral atoms and 82% of emission intensity in front of the wall. The influence of atomic and molecular processes on the energy balance is discussed for the scrape-off layer (SOL), and the power loss from molecular dissociation is found to be 6×10^4kW at the SOL. The ion Bernstein wave (IBW) can effectively suppress the magnetohydrodynamic behaviour, the fluctuation levels and the turbulence; the D_⊥ in front of the limiter declines from 0.84 to 0.2m^2·s^{-1} and the particle confinement time rises from 9 to 12ms. %K plasma %K diffusion %K coefficients %K energy %K profile %K atomic %K and %K molecular %K processes %K simulation %K of %K D_α %K line %K shape %U http://www.alljournals.cn/get_abstract_url.aspx?pcid=6E709DC38FA1D09A4B578DD0906875B5B44D4D294832BB8E&cid=47EA7CFDDEBB28E0&jid=CD8D6A6897B9334F09D8D1648C376FB4&aid=0DC95E69C35FBE17F1776A27330118EC&yid=D0E58B75BFD8E51C&vid=FC0714F8D2EB605D&iid=9CF7A0430CBB2DFD&sid=C32BEECEF5323D34&eid=6F185A924223F19E&journal_id=1009-1963&journal_name=中国物理&referenced_num=0&reference_num=13