摘要
Sheath potential coefficient α is a key parameter, which is used to estimate plasma potential(Vp)for edge plasma physics study. Recently, a series of experiments has been carried out under hydrogen plasmas in the J-TEXT tokamak with swept probe, which is employed for current–voltage(I–V) characteristic measurement. Electron temperature is evaluated from I–V curve by three-parameter fitting method, and the electron energy probability function shows that electron distribution is Maxwellian both outside and inside of last closed flux surface(LCFS). Plasma potential is obtained by crossing point between I–V exponential fitting curve and electron saturation current extrapolating line, which is in good agreement with first derivative probe technique. The α coefficient profile in the vicinity of the LCFS is obtained, which is in the range of 2.1–3, and decreases from outside to inside of LCFS.
作者
赵伟
聂林
严龙文
许敏
柯锐
阳杰
陈志鹏
王占辉
王雅丽
J-TEXT Team
Wei ZHAO;Lin NIE;Longwen YAN;Min XU;Rui KE;Jie YANG;Zhipeng CHEN;Zhanhui WANG;Yali WANG;J-TEXT Team(Southwestem Institute of Physics,Chengdu 610041,People's Republic of China;College of Electrial and Electronic Engineering,Huazhong University of Science and Technology,Wuhan 430074,People's Republic of China)
基金
supported by the National Key Research and Development Program of China (No. 2018YFE0309103)
National Natural Science Foundation of China (Nos. 11875020, 11705052, 11875124 and U1867222)
the ITER Organization and China Domestic Agency for the support of this work (ITER5.5.P01.CN.05)。