Method for experimental determination of Z dependence of impurity transport on JET
Method for experimental determination of Z dependence of impurity transport on JET
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DOI：
10.1088/0029-5515/47/4/010
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发表时间：
2007-04
期刊：
影响因子：
3.3
通讯作者：
C. Giroud;R. Barnsley;P. Buratti;I. Coffey;M. von Hellermann;C. Jupén;K. Lawson;A. Meigs;M. O’Mul
中科院分区：
文献类型：
--
作者：
C. Giroud;R. Barnsley;P. Buratti;I. Coffey;M. von Hellermann;C. Jupén;K. Lawson;A. Meigs;M. O’Mul
为了预测ITER等未来聚变装置中杂质峰的出现，需要研究现有装置中杂质输运对Z的依赖关系。在本文中，我们描述了一种新的技术，以确定不同的原子序数的杂质的运输独立。一种技术已被开发，允许同时测量的运输Ne和Ar在同一放电，同时最大限度地减少系统误差的光谱测量。在杂质输运模拟中实现了电荷交换测量密度、绝对真空紫外线强度和绝对软X射线强度的再现。本文介绍了氖（Ne）和氩（Ar）输运系数误差的估算方法。在等离子体区域中的扩散和对流系数确定为混合放电，观察到的Ne和Ar的运输超过新古典预测。在相同的区域中，两种杂质的扩散系数相似。Ne和Ar的对流系数也相当。Ne和Ar密度分布的峰值是可比的间歇性缓慢重连n = 1模式是稳定的，在这些混合放电期间。
The prediction of impurity peaking in future fusion devices such as ITER necessitates the study of the dependence on Z of the impurity transport in present devices. In this paper we describe a novel technique to determine the transport of impurities with different atomic numbers independently. A technique has been developed that allows simultaneously the measurement of the transport of Ne and Ar in the same discharge while minimizing the systematic errors in the spectroscopic measurements. The reproduction of the charge-exchange measured densities, absolute vaccum ultra-violet line intensities and absolute soft x-ray intensity is achieved in an impurity transport simulation. The method used to estimate the errors on the transport coefficients of neon (Ne) and argon (Ar) is presented. In the plasma region where the diffusion and convection coefficients are determined for hybrid discharges, the transport of Ne and Ar is observed to exceed neoclassical predictions. In the same regions, the diffusion coefficients of both impurities are similar. The convection coefficients are also comparable for Ne and Ar. The peaking of Ne and Ar density profiles are comparable during the period where the intermittent slow reconnecting n = 1 mode is stable in these hybrid discharges.