Polarimetric Thomson scattering for high Te fusion plasmas

Polarimetric Thomson scattering (TS) is a technique for the analysis of TS spectra in which the electron temperature Te is determined from the depolarization of the scattered radiation, a relativistic effect noticeable only in very hot (Te ≥ 10 keV) fusion plasmas. It has been proposed as a complementary technique to supplement the conventional spectral analysis in the ITER CPTS (Core Plasma Thomson Scattering) system for measurements in high Te, low ne plasma conditions. In this paper we review the characteristics of the depolarized TS radiation with special emphasis to the conditions of the ITER CPTS system and we describe a possible implementation of this diagnostic method suitable to significantly improve the performances of the conventional TS spectral analysis in the high Te range.