Tore-Supra X-ray pulse-height analyzer diagnostic
For investigations of the physical mechanisms of LHCD in a tokamak plasma (propagation and absorption of the wave), the build-up of the momentum distribution function of tail electrons with the injection of LH waves must be known. One of the more straightforward methods for determination of the characteristics of the fast electrons is to determine the X-ray bremsstrahlung emission of the plasma. For this purpose, an X-ray spectrometer was installed on Tore Supra, which can analyse, with time resolution, radiations in the energy range 30-1000 keV along five chords in the same poloidal plane. The first results obtained are presented. When LH waves are launched into the plasma, a well-defined X-ray emission is measured up to 300-500 keV. The shape of the energy spectrum is almost independent of the line of sight for low density plasmas, except for the most peripheral. For high density regimes, the plasma X-ray emission becomes hollow and a variation of the slope of the energy spectrum from one line of sight to another is clearly observed.
Bibliographic Reference: Paper presented: 18th European Conference of the EPS-Plasma Physics Division, Berlin (DE), June 3-7, 1991
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Record Number: 199110361 / Last updated on: 1994-12-02
Original language: en
Available languages: en