Ren X H, Yang Z J, Shi Z B, Yang Z C, Zha X Q, Gao Y, Zhang Z C
International Joint Research Laboratory of Magnetic Confinement Fusion and Plasma Physics, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
Southwestern Institute of Physics, P. O. Box 432, Chengdu 610041, China.
Rev Sci Instrum. 2021 Mar 1;92(3):033545. doi: 10.1063/5.0040915.
Doppler reflectometer is a powerful diagnostic tool to study the turbulence for tokamak plasmas. It can provide information on the density fluctuation, the poloidal rotation, the radial electric field, its shear, etc. A tunable multi-channel V-band (50-75 GHz) Doppler reflectometer system has been developed on the J-TEXT tokamak for the measurement under various toroidal magnetic fields. A universal serial bus controlled synthesizer is used as a source that can adjust the probing frequency remotely. This Doppler reflectometer can measure the plasma in 0.3 < ρ < 1 . Its radial resolution is <2 cm, and k is ∼ 4-12 cm. Based on the Doppler reflectometer, the perpendicular turbulence propagation velocity, the profile of the radial electric field, the geodesic acoustic mode, and some other phenomena have been observed on J-TEXT.
