An E-band (60–90 GHz) tunable ten-channel backscattering and one-channel forward-scattering integrated Doppler reflectometer with X-mode polarization has been installed on the O port of the Experimental Advanced Superconducting Tokamak. The ten-channel backscattering system can launch 16 fixed microwave beams in the range of 60–90 GHz with an interval of 2 GHz into the plasma, and 10 probing signals are selected by employing a reference signal and multiple filters. It can measure the turbulence at 10 different radial locations simultaneously. In addition, by the backscattered and forward-scattered signals, this integrated system can measure multi-scale turbulence at the same location. During experiments, the frequency of the reference signals is tunable in the E-band, and the selected probing signals can be changed as needed in 100 . Furthermore, the incident angle can be adjusted from −10° to 20°, and the wavenumber range is 4–25 cm−1 with a wavenumber resolution of Δk/k ⩽ 0.28. The scattering locations and the perpendicular wavenumber are calculated by ray tracing in the experiments.
This paper describes an advanced reflectometer system that can measure multi-scale turbulence in fusion plasmas. The system uses E-band microwaves to probe the plasma at 10 different radial locations simultaneously, providing detailed information about turbulence across various scales.