Poloidal magnetic field reconstruction by laser-driven ion-beam trace probe in spherical tokamak  

作　　者：Zuyu ZHANG Tianchao XU Chijie XIAO Xianli HUANG Renchuan HE Ruixin YUAN Xiaoyi YANG 张祖煜;徐田超;肖池阶;黄贤礼;何任川;袁瑞鑫;杨肖易(State Key Laboratory of Nuclear Physics and Technology,School of Physics,Peking University,Beijing 100871,People’s Republic of China;ENN Science and Technology Development Co.Ltd.,Langfang 065001,People’s Republic of China;Harbin Institute of Technology,Harbin 150001,People’s Republic of China)

机构地区：[1]State Key Laboratory of Nuclear Physics and Technology,School of Physics,Peking University,Beijing 100871,People’s Republic of China [2]ENN Science and Technology Development Co.Ltd.,Langfang 065001,People’s Republic of China [3]Harbin Institute of Technology,Harbin 150001,People’s Republic of China

出　　处：《Plasma Science and Technology》2024年第11期58-64,共7页等离子体科学和技术（英文版）

基　　金：the support of National Key Research and Development Program of China (No. 2022YFA1604600);State Key Laboratory of Advanced Electromagnetic Technology。

摘　　要：The poloidal magnetic field( B_(p)) plays a critical role in plasma equilibrium, confinement and transport of magnetic confinement devices. Multiple diagnostic methods are needed to complement each other to obtain a more accurate B_(p) profile. Recently, the laser-driven ion-beam trace probe(LITP) has been proposed as a promising tool for diagnosing B_(p) and radial electric field( E_(r)) profiles in tokamaks [Yang X Y et al 2014 Rev. Sci. Instrum. 85 11E429]. The spherical tokamak(ST) is a promising compact device with high plasma beta and naturally large elongation. However, when applying LITP to diagnosing B_(p) in STs, the larger B_(p) invalidates the linear reconstruction relationship for conventional tokamaks, necessitating the development of a nonlinear reconstruction principle tailored to STs. This novel approach employs an iterative reconstruction method based on Newton's method to solve the nonlinear equation. Subsequently,a simulation model to reconstruct the B_(p) profile of STs is developed and the experimental setup of LITP is designed for EXL-50, a middle-sized ST. Simulation results of the reconstruction show that the relative errors of B_(p) reconstruction are mostly below 5%. Moreover, even with 5 mm measurement error on beam traces or 1 cm flux surface shape error, the average relative error of reconstruction remains below 15%, initially demonstrating the robustness of LITP in diagnosing B_(p) profiles in STs.

关 键 词：laser-driven ion-beam trace probe poloidal magnetic field diagnostic iterative reconstruction 

分 类 号：TL631.24[核科学技术—核技术及应用]