%0 Journal Article
%T Evolution of local ideal helical perturbations in cylindrical plasma<br>Evolution　of　local　ideal　helical　perturbations　in　cylindrical　plasma
%A Zhang Wen-Lu
%A Li Ding
%A <br>张文禄
%A 李定
%J 中国物理 B
%D 2004
%I 
%X The evolution of a local helical perturbation and its stability property for arbitrary magnetic shear configurations are investigated for the case of in cylindrical geometry. An analytic stability criterion has been obtained which predicts that a strong magnetic shear will enhance the instability in the positive shear region but enhance the stability in the negative shear region. The perturbations with the poloidal and toroidal perturbation mode numbers m/n=1/1 is most unstable due to the stabilizing terms increasing with m. For m/n=1/1 local perturbations in the conventional positive magnetic shear (PMS) configurations, a larger q_{min} exhibits a weaker shear in the core and is favourable to the stability, while in the reversed magnetic shear (RMS) configurations, a larger q_0 corresponds to a stronger positive shear in the middle region, which enhances the instability. No instabilities are found for m≥2 local perturbations. The stability for RMS configuration is not better than that for PMS configuration.
%K time expanding method
%K local ideal helical perturbation
%K cylindrical plasma<br>圆柱形等离子体
%K 螺旋形微扰
%K 稳定性能
%K 磁剪切
%K 时间展开理论
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=6E709DC38FA1D09A4B578DD0906875B5B44D4D294832BB8E&cid=47EA7CFDDEBB28E0&jid=CD8D6A6897B9334F09D8D1648C376FB4&aid=AAB6ECB059E0C01ECCFAFBE2F0446206&yid=D0E58B75BFD8E51C&vid=FC0714F8D2EB605D&iid=9CF7A0430CBB2DFD&sid=4C25EB18BC5AA509&eid=AEA8CA70A6C58E24&journal_id=1009-1963&journal_name=中国物理&referenced_num=0&reference_num=15