Parametric decay instabilities of lower hybrid waves on CFETR  

作　　者：Taotao Zhou Nong Xiang Chunyun Gan Guozhang Jia Jiale Chen 周涛涛;项农;甘春芸;贾国章;陈佳乐(Institute of Plasma Physics,Hefei Institutes of Physical Science,Chinese Academy of Sciences,Hefei 230031,China;University of Science and Technology of China,Hefei 230026,China;Centre of Magnetic Fusion Theory,Chinese Academy of Sciences,Hefei 230031,China)

机构地区：[1]Institute of Plasma Physics,Hefei Institutes of Physical Science,Chinese Academy of Sciences,Hefei 230031,China [2]University of Science and Technology of China,Hefei 230026,China [3]Centre of Magnetic Fusion Theory,Chinese Academy of Sciences,Hefei 230031,China

出　　处：《Chinese Physics B》2022年第9期386-396,共11页中国物理B（英文版）

基　　金：Project supported by the National Key Research and Development Program of China(Grant Nos.2017YFE0300406 and 2019YFE00308050);the National Natural Science Foundation of China(Grant Nos.11975272,12175274,12005258,and 11705236)。

摘　　要：The lower hybrid current drive is a potential candidate for sustaining plasma current in tokamak steady-state oper-ations,which could be used in China Fusion Engineering Test Reactor(CFETR)with input power up to a few tens of megawatts.Such high input power could trigger the well-known parametric instabilities(PIs)at the plasma edge affect-ing the propagation and absorption of the lower hybrid pump waves.By analytically solving the nonlinear dispersion relation describing PIs,an explicit expression of the PI growth rate is obtained and analyzed in detail.It is found that pressure is the key parameter determining the PI characteristics.Ion sound quasi-mode is the dominant decay channel in the low-pressure regime,while the ion cyclotron quasi-mode(ICQM),as well as its harmonics,becomes dominant in the intermediate regime.In the high-pressure regime,only one mixed channel is found,which is related to Landau damping by free-streaming ions.Analytical expressions of growth rates of these decay channels are also obtained to show the parameter dependence at different pressure limits.The above analytical results are used to estimate the PIs on a typical profile of CFETR,and verified by corresponding numerical calculations.ICQM is found to be the strongest decay channel with a considerable growth rate for CFETR.

关 键 词：lower hybrid parametric instability CFETR 

分 类 号：TL631.24[核科学技术—核技术及应用]