Tungsten control in type-I ELMy H-mode plasmas on EAST  

作　　者：Zong Xu Zhen-Wei Wu Ling Zhang Yun-Xing Cheng Wei Gao Xiao-Dong Lin Xiang Gao Ying-Jie Chen Yue-Heng Huang Juan Huang Qing Zang Yin-Xian Jie Yan-Min Duan Ying-Ying Li Hai-Qing Liu Guo-Sheng Xu EAST team 

机构地区：[1]Advanced Energy Research Center,Shenzhen University,Shenzhen 518060,China [2]Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province,College of Optoelectronic Engineering,Shenzhen University,Shenzhen 518060,China [3]Institute of Plasma Physics,Chinese Academy of Science,Hefei 230031,China [4]University of Science&Technology of China,Hefei 230031,China

出　　处：《Nuclear Science and Techniques》2021年第9期61-72,共12页核技术（英文）

基　　金：supported by the National Key R&D Program of China(Nos.2018YFE0311100 and 2017YFE0301205);National Natural Science Foundation of China(Nos.11905146,11775269,11575244,11575249,11575235,11422546,11805133,and U19A20113);Users with Excellence Program of Hefei Science Center,CAS(No.2019HSC-UE014);National Magnetic Confinement Fusion Science Program of China(Nos.2015GB110005,2015GB103003,2015GB101002,and 2015GB103000);Key Research Program of Frontier Sciences,CAS(No.QYZDB-SSWSLH001);CASHIPS Director’s Fund(No.BJPY2019A01);Shenzhen Clean Energy Research Institute.

摘　　要：The first experimental investigation of the tungsten behavior in ELMy H-mode plasmas with co-/counter neutral beam injection(NBI)and unfavor-able/favorable B t was performed on EAST.Tungsten was found to accumulate easily in ELMy H-mode plasma with co-NBI heating and unfavorable B t.Thus,in this case the tungsten concentration can exceed 10^(-4),resulting in degradation of the plasma confinement and periodic H–L transitions.To reduce the tungsten concentration in steady-state type-I ELMy H-mode operation,counter-NBI is applied to modify the density and temperature and brake the plasma toroidal rotation.The applied counter-NBI decreases the PHZ+E_(r) inward pinch velocity and rever-ses the direction of neoclassical inward convection,thus decreasing the tungsten concentration from-7×10^(-5) to-2×10^(-5) in type-I ELMy H-mode plasma with favorable B_(t).A comparison of the effects of different B_(t) directions on the tungsten behavior also shows that favor-able B_(t) is beneficial for reducing the tungsten concentration in the core plasma.These results imply that counter-NBI with favorable B_(t) can effectively prevent tungsten accu-mulation and expand the operating window for exploring steady-state type-I ELMy H-mode operation of EAST.

关 键 词：Tungsten accumulation Counter-NBI Favorable B_(t)ELMy H-mode EAST 

分 类 号：TL631.24[核科学技术—核技术及应用]