Edge and Core Impurity Transport Study with Spectroscopic Instruments in LHD
Edge and Core Impurity Transport Study with Spectroscopic Instruments in LHD
复制标题
DOI：
10.1088/1009-0630/11/4/07
复制
发表时间：
2009-08
影响因子：
1.7
通讯作者：
S. Morita;M. Goto;M. Kobayashi;S. Muto;M. Chowdhuri;Dong Chunfeng;Zhou Hangyu;Cui Zhengying;K. Fujii;A. Furuzawa;M. Hasuo;A. Iwamae;Jie Yin-xian;M. Koubiti;I. Sakurai;Y. Tawara;Wan Baonian;Wu Zhenwei;N. Yamaguchi
中科院分区：
文献类型：
--
作者：
S. Morita;M. Goto;M. Kobayashi;S. Muto;M. Chowdhuri;Dong Chunfeng;Zhou Hangyu;Cui Zhengying;K. Fujii;A. Furuzawa;M. Hasuo;A. Iwamae;Jie Yin-xian;M. Koubiti;I. Sakurai;Y. Tawara;Wan Baonian;Wu Zhenwei;N. Yamaguchi
利用先进的可测量杂质一维和二维分布的光谱仪器，研究了大型螺旋装置（LHD）中边缘和核心区域的杂质输运。利用CIII（977°c）、CIV（1548°c）、CV（40.3°c）和CVI（33.7°c）在不同电离阶段的4种碳共振跃迁研究了边缘杂质行为。当线平均电子密度ne从1增加到6 ？1013厘米吗?（CIII+CIV）/ne的比值增大，(CV+CVI)/ne的比值减小。其中CIII+CIV （CV+CVI）表示CIII （CV）和CIV （CVI）强度之和。CIII+CIV表示碳流入，CV+CVI表示通过遍历层运输的排放。这一结果为LHD中遍历层对杂质的筛选提供了实验证据，并得到了三维边缘粒子模拟的支持。本文还研究了高密度放电(ne ？1 ?1015厘米吗?3)多粒h2注射。结果表明，注入颗粒后，对流速度比V/D （V：对流速度，扩散系数D：扩散系数）减小，Zeff曲线在1.1 ~ 1.2范围内呈平坦曲线。这些结果证实在高密度放电中没有杂质堆积。结果，铁的密度nFe分析为6 ？10？7 (= nFe/ne)，即使在这种高密度放电中，其量也可以忽略不计。本文还介绍了为进一步研究杂质输运而新开发的空间分辨VUV和EUV光谱仪的一维和二维杂质分布及其初步结果。
Impurity transport was investigated at both edge and core regions in large helical device (LHD) with developed spectroscopic instruments which can measure one- and two-dimensional distributions of impurities. The edge impurity behavior was studied recently using four carbon resonant transitions in different ionization stages of CIII (977?), CIV (1548?), CV (40.3?) and CVI (33.7?). When the line-averaged electron density, ne, is increased from 1 to 6 ? 1013 cm?3, the ratio of (CIII+CIV)/ne increases while the ratio of (CV+CVI)/ne decreases. Here, CIII+CIV (CV+CVI) expresses the sum of CIII (CV) and CIV (CVI) intensities. The CIII+CIV indicates the carbon influx and the CV+CVI indicates the emissions through the transport in the ergodic layer. The result thus gives experimental evidence on the impurity screening by the ergodic layer in LHD, which is also supported by a three-dimensional edge particle simulation. The core impurity behavior is also studied in high-density discharges (ne ? 1? 1015 cm?3) with multi H2-pellets injection. It is found that the ratio of V/D (V: convection velocity, D: diffusion coefficient) decreases after pellet injection and Zeff profile shows a flat one at values of 1.1?1.2. These results confirm no impurity accumulation occurs in high-density discharges. As a result, the iron density, nFe, is analyzed to be 6 ? 10?7 ( = nFe/ne) of which the amount can be negligible as radiation source even in such high-density discharges. One- and two-dimensional impurity distributions from space-resolved VUV and EUV spectrometers newly developed for further impurity transport study are also presented with their preliminary results.