Rutherford Scattering at Textor

The Rutherford scattering diagnostic at TEXTOR is used to perform temporal and spatial resolved measurements of the ion temperature. Function parametrization techniques are used for fast analysis of the complex spectra, which also contain information about the presence of impurities in the scattering volume. The (perpendicular) central ion temperature has been determined for a series of discharges, where neutral beam coinjection (hydrogen) was applied to plasmas of different densities. A temperature of 2.8 keV was found for a line-averaged electron density of 1.5 X 10(19) m-3, decreasing monotonically for higher densities to 0.8 keV at 6.0 X 10(19) m-3. When deuterium was used as heating beam species, scattering on a high-Z impurity, probably tungsten from the filaments of the NBI sources, gave a dominant contribution to the spectra.