Derivation of local impurity transport quantities from soft-x radiation evolution during tracer injection at W7-AS
Derivation of local impurity transport quantities from soft-x radiation evolution during tracer injection at W7-AS
复制标题
从 W7-AS 示踪剂注入过程中的 soft-x 辐射演化推导局部杂质传输量
DOI：
10.1063/1.1149357
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发表时间：
1999
期刊：
影响因子：
--
通讯作者：
A. Weller
中科院分区：
文献类型：
--
作者：
R. Burhenn;A. Weller
分析注入示踪杂质的杂质密度随时间和径向的演化规律是确定杂质输运系数的一种常用方法。在不能直接测量杂质密度的情况下，例如，通过有源电荷交换复合光谱，杂质密度必须从测量的杂质辐射重建，例如，软X相机拍摄由于能量积分信息，关于空间电离态分布的假设，例如，日冕平衡是必要的这在大型运输的情况下可能无效。因此，在径向日冕分布的初步假设下导出的输运量再次以迭代的方式用于改进密度重建，以接近更真实的输运量。该程序被应用到仿星器温德尔斯坦7-AS的等离子体放电。
A frequently used method for determination of impurity transport coefficients is the analysis of the radial and temporal time evolution of the impurity density of injected tracer impurities. In cases when the impurity density cannot be measured directly, e.g., by active charge exchange recombination spectroscopy, the impurity density has to be reconstructed from impurity radiation as measured, e.g., by the soft-x camera. Due to the energy integrated information, assumption about the spatial ionization state distribution, e.g., coronal equilibrium, is necessary. This might not be valid in cases of large transport. Consequently, the transport quantities, derived under the preliminary assumption of radial coronal distribution, are used again in an iterative way to improve the density reconstruction in order to approach more realistic transport quantities. The procedure was applied to plasma discharges in the stellarator Wendelstein 7-AS.