EAST托卡马克上截面效应对电荷交换复合光谱测量结果的影响

离子温度和旋转速度是聚变等离子体中的重要物理参数,在先进实验超导托卡马克EAST(Experimental Advanced Superconducting Tokamak)上电荷交换复合光谱(Charge e Xchange Recombination Spectroscopy,CXRS)诊断是测量这些物理参数的标配诊断之一。由于截面效应的存在,CXRS诊断测量的谱线线型会受到影响,导致得到的离子温度和旋转速度偏离实际值,为了得到真实值,需要对离子温度和旋转速度进行修正。在EAST上,分别采用常用的动力学理论和数值计算方法对测量到的实验数据进行修正,同时对比两种方法对截面效应的修正结果,可以看出两种方法得到的结果趋势基本一致。对2015年EAST上电荷交换复合光谱测量到的典型的实验数据进行修正,结果表明在目前的放电条件下截面效应对离子温度的影响比较小,而对旋转速度的影响低于10%。

Cross-section effect on charge exchange recombination spectroscopy measurement with the EAST tokamak

Background:Charge-exchange spectroscopy is a powerful diagnostic tool for determining ion temperatures and rotational velocities in tokamak plasmas. This technique depends on detailed understanding of the atomic physics processes that affect the measured apparent velocities with respect to the true ion rotational velocities. Purpose:The study aims to give correction to Charge eXchange Recombination Spectroscopy (CXRS) measurement with Experimental Advanced Superconducting Tokamak (EAST) because of energy dependence of the charge-exchange cross-sections.Methods: Kinetic theory and numerical approximationof cross-section effects are usually used to evaluate the associated corrections. On EAST, kinetic theory and numerical approximation of cross-section effects will be applied to calculate the corrections.Results: A direct comparison between kinetic theory and numerical approximation of cross-section effects will be given. And kinetic theory is applied to give correction to the CXRS measure data in 2015.Conclusion: The correction results showed that two ways are feasible and charge-exchange cross-section effect has more influence on rotational velocity. It gives a possible way for the CXRS data correction because of charge-exchange cross-section effect.