刮削层内低杂波波散射全波解数值模拟研究  

Numerical simulation study of lower hybrid wave scattering full-wave solution in scrap-off layer

作　　者：杨镜禾 丁伯江 吴陈斌 李妙辉 王茂 刘亮 闫广厚 YANG Jinghe;DING Bojiang;WU Chenbin;LI Miaohui;WANG Mao;LIU Liang;YAN Guanghou(Institute of Plasma Science,Hefei Institutes of Physical Science,Chinese Academy of Sciences,Hefei 230031,China;University of Science and Technology of China,Hefei 230026,China)

机构地区：[1]中国科学院合肥物质科学研究院等离子体物理研究所,合肥230031 [2]中国科学技术大学,合肥230026

出　　处：《核技术》2024年第5期145-150,共6页Nuclear Techniques

基　　金：国家自然科学基金(No.12305253,No.11975266);中国科学院合肥物质研究院院长基金(No.YZJJ2023QN24)资助。

摘　　要：低杂波电流驱动(Lower Hybrid Current Drive,LHCD)是托卡马克的主要辅助加热与电流驱动方式之一,研究表明,低杂波在刮削层内的边界寄生效应会显著降低低杂波电流驱动效率。其中,边界密度涨落引起的波散射会导致刮削层内的低杂波波谱变化,从而改变低杂波功率沉积位置和电流驱动效率。本文使用全波解方法研究全超导托卡马克(Experimental Advanced Superconducting Tokamak,EAST)装置上刮削层内密度涨落导致的低杂波波散射,重点分析不同特征的低频电子密度涨落对波散射的影响。模拟结果表明:密度波包(blob)引起的散射导致低杂波功率流的空间结构的改变,blob造成的背向散射比前向散射更明显;blob内的密度涨落大小主要影响波场扰动幅度,blob的半径主要影响波散射的空间范围,多个blob造成的全场扰动显著增加。[Background]Lower hybrid current drive(LHCD)is one of the main auxiliary heating and current driving methods for Tokamak,and studies have shown that the boundary parasitics effect of lower hybrid(LH)wave in scrap-off layer(SOL)significantly decreases current drive efficiency of LH wave.Among these,wave scattering caused by density fluctuation at the boundary results in spectral changes within the SOL,which changes the power deposition location and current drive efficiency.[Purpose]This study aims to explore the lower hybrid scattering caused by density fluctuation in the scrap-off layer on the Experimental Advanced Superconducting Tokamak(EAST)device.[Methods]Based on the cold plasma dispersion theory and the blob density fluctuation theory,COMSOL Multiphysics was employed to establish a full-wave solution model of lower hybrid scattering in the SOL.Based on the parameters of the EAST device,the influence of low-frequency electron density fluctuation with different characteristics on wave scattering was analyzed.[Results]The simulation results show that the backscattering direction caused by the density wave packet"blob"is more obvious than the forward scattering,and scattering induced by blob leads to the change of spatial structure of low hybrid power flow.The density fluctuation in the blob mainly affects the amplitude of the wave field disturbance,the radius of the blob mainly affects the spatial range of the wave scattering,the full-field disturbance caused by multiple blobs increases significantly.[Conclusions]The full-wave solution model of the SOL established in this study is reliable.The simulation results using this model show that the density fluctuation will cause lower hybrid scattering,which will change the spatial structure of the power flow.

关 键 词：低杂波电流驱动 波散射 全波解 刮削层 低频电子密度涨落 

分 类 号：TL99[核科学技术—核技术及应用]