Measurement of deuterium ion temperature profiles at TEXTOR-94

Charge-exchange recombination spectroscopy (CXRS) has been used to compare results on ion temperatures from several diagnostics at TEXTOR-94. The question of whether the typically measured width of impurity spectral lines is representative for the main ion temperature T-I, is addressed by applying CXRS to the Palmer-alpha spectrum of deuterium. The importance of the halo effect is found not to be severe for the T-I measurements. T-I is lower than the impurity temperatures for low-density discharges with neutral beam heating. The time evolution of T-I and the toroidal rotation were also measured during sawtooth oscillations. From this a lower bound for the ion heat diffusivity chi(I)(HP) of approximate to 2 m(2) s(-1) has been deduced.