X-mode reflectometry for magnetohydrodynamic activity associated with q=1 surface measurements on Tore Supra
Tore Supra is equipped with two 20 ms fast sweep X-mode reflectometers operating between 50-110 GHz dedicated to density profile determination and an X-mode fixed frequency reflectometer operating between 105�155 GHz for density fluctuation measurements. Heterodyne and sine-cosine detection provide measurements of the reflected signal with high sensitivity. Operating profile reflectometer in burst mode (5 ms dead time between two consecutive sweeps) allows quasi-simultaneous measurements at fixed frequency over a broad frequency band. Thus, information on plasma fluctuations, such as magnetohydrodynamic (MHD) activity, up to 20 kHz as well as a radial localization of the modes is accessible. The temporal evolution of the q=1 rational surface during sawtooth crash activity has been recorded in the plasma center with high spatial resolution. In addition, a direct comparison between signals associated with a central MHD mode from both profile and fluctuation reflectometers, positioned at different toroidal angles, allows one to determine the plasma toroidal velocity.
Bibliographic Reference: An article published in: Review of Scientific Instruments, Vol. 75, n° 10, p. 3825-3827
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Record Number: 200518349 / Last updated on: 2005-10-04
Original language: en
Available languages: en