High resolution multiposition Thomson scattering for the TEXTOR tokamak

In this article, the recently installed high resolution multiposition Thomson scattering (TS) system of the TEXTOR tokamak is presented. Light from a pulsed ruby laser is scattered by the free electrons of the plasma and transmitted by fiber optics to a polychromator for spectral analysis. The Doppler broadened spectrum of the scattered light is analyzed with a Littrow spectrometer, detected with an image intensifier, and recorded with two intensified charge coupled device cameras. Values of the electron temperature (T-e) in the range of 50 eV up to 4 keV can be measured at 450 spatial elements of 2 mm along a chord of 900 mm, with a resolution of 8 mm. The observational error on T-e was found to be