1. Microwave reflectometer for density profile and turbulence measurements on the COMPASS tokamak.
- Author
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Bogar O, Zajac J, Zacek F, Varavin M, Hron M, Panek R, and Silva A
- Abstract
The fast microwave reflectometer system on the COMPASS tokamak consists of an O-mode polarized K-band (18 GHz-26 GHz), Ka-band (26 GHz-40 GHz), and a part of U-band (40 GHz-54 GHz). The plasma density profile from the edge plasma area is measured using a fast sweeping rate up of to 6 µs of the probing wave. The processing of the reflected signal is realized by the heterodyne detection configuration based on the I/Q modulator. Two different methods of dynamic calibration of the required linear sweep frequency, together with static frequency and dispersion calibration, were used. The electron density profile was reconstructed by a spectrogram-based method with four sweeps on average. The system has the capability to measure the mid-plane low-field side electron density profile in the density range from 4 × 10
18 m-3 to 3.6 × 1019 m-3 . Experimental results obtained on COMPASS discharges are presented to demonstrate the performance of the diagnostics.- Published
- 2020
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