Measurement of electron density by microwave reflectometry in Tore Supra
Reflectometry experiments are carried out in tokamaks in order to make local measurements of the electron density of the plasma, knowledge of which is essential to an understanding of the power balance of reactors. The experiments have made it possible to measure phase difference between a reference wave and the wave reflected by the plasma, for different values of the F wave. In the apparatus fitted to Tore Supra, the wave was emitted at normal incidence to the plasma in the equatorial plane of the tokamak, at a frequency in linear relationship to time. The entire system comprises three reflectometers, covering a frequency range of between 25 and 75 GHz, allowing electron density measurement within a few milliseconds. Changes in the density profile as a function of time made it possible to observe the injection of deuterium pellets into the plasma and the effect of the ergodic divertor in the edge plasma. In practice, it should also be possible to detect MHD modes and changes in these, and to locate the resonating surfaces where instabilities are set off.
Bibliographic Reference: Paper presented: Troisième Congrès de la Société Française de Physique - Plasma, Nancy (FR), September 16-18, 1992
Availability: Available from (1) as Paper FR 37074 ORA
Record Number: 199211488 / Last updated on: 1994-11-29
Original language: fr
Available languages: fr