首页|Forward modelling of the Cotton-Mouton effect polarimetry on EAST tokamak

Forward modelling of the Cotton-Mouton effect polarimetry on EAST tokamak

扫码查看
Measurement of plasma electron density by far-infrared laser polarimetry has become a routine and indispensable tool in magnetic confinement fusion research.This article presents the design of a Cotton-Mouton polarimeter interferometer,which provides a reliable density measurement without fringe jumps.Cotton-Mouton effect on Experimental Advanced Superconducting Tokamak(EAST)is studied by Stokes equation with three parameters(s1,s2,s3).It demonstrates that under the condition of a small Cotton-Mouton effect,parameter s2 contains information about Cotton-Mouton effect which is proportional to the line-integrated density.For a typical EAST plasma,the magnitude of Cotton-Mouton effects is less than 2π for laser wavelength of 432 μm.Refractive effect due to density gradient is calculated to be negligible.Time modulation of Stokes parameters(s2,s3)provides heterodyne measurement.Due to the instabilities arising from laser oscillation and beam refraction in plasmas,it is necessary for the system to be insensitive to variations in the amplitude of the detection signal.Furthermore,it is shown that non-equal amplitude of X-mode and O-mode within a certain range only affects the DC offset of Stokes parameters(s2,s3)but does not greatly influence the phase measurements of Cotton-Mouton effects.

EASTCotton-Mouton effectpolarimeter interferometerelectron density measurementStokes vector

沈敏勇、张际波、张耀、揭银先、刘海庆、谢锦林、丁卫星

展开 >

School of Nuclear Science and Technology,University of Science and Technology of China,Hefei 230026,People's Republic of China

Institute of Plasma Physics,Chinese Academy of Sciences,Hefei 230031,People's Republic of China

国家自然科学基金

12127809

2024

等离子体科学和技术(英文版)
中国科学院合肥物质科学研究所 中国力学学会

等离子体科学和技术(英文版)

EI
影响因子:0.297
ISSN:1009-0630
年,卷(期):2024.26(3)
  • 25