Ray Tracing for Doppler Backscattering System in the Experimental Advanced Superconducting Tokamak  

作　　者：周楚 刘阿娣 胡建强 王明远 张小辉 李弘 俞昌旋 刘万东 兰涛 谢锦林 

机构地区：[1]CAS Key Laboratory of Geospace Environment,Department of Modern Physics,University of Science and Technology of China

出　　处：《Plasma Science and Technology》2015年第9期728-732,共5页等离子体科学和技术（英文版）

基　　金：supported by National Natural Science Foundation of China(Nos.10990211 and 11105146);the ITER-CN Project;973 Program of China(No.2013GB106002)

摘　　要：The Doppler backscattering system has been widely used for turbulence measurements,and the microwave beam will be backscattered near the cut-off layer when the Brag condition is fulfilled.In tokamak,the ray-tracing code is used to obtain the radial position and perpendicular wave number of the scattering layer for turbulence velocity measurement and the WKB（Wentzel-Kramers-Brillouin） approximation should be satisfied for optical propagation.To calculate the backscattering location and wave number at the cut-off layer only,a single ray tracing in the cross section is enough,while for spatial and wave number resolution calculation,multiple rays reflecting the microwave beam size should be used.Considering the angle between the wave vector and the magnetic field,a three-dimension quasi-optical Gaussian ray tracing is sometimes needed.The Doppler backscattering system has been widely used for turbulence measurements,and the microwave beam will be backscattered near the cut-off layer when the Brag condition is fulfilled.In tokamak,the ray-tracing code is used to obtain the radial position and perpendicular wave number of the scattering layer for turbulence velocity measurement and the WKB（Wentzel-Kramers-Brillouin） approximation should be satisfied for optical propagation.To calculate the backscattering location and wave number at the cut-off layer only,a single ray tracing in the cross section is enough,while for spatial and wave number resolution calculation,multiple rays reflecting the microwave beam size should be used.Considering the angle between the wave vector and the magnetic field,a three-dimension quasi-optical Gaussian ray tracing is sometimes needed.

关 键 词：Doppler backscattering system ray tracing wave number resolution pitch angle 

分 类 号：TL631.24[核科学技术—核技术及应用]