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

1st Measurements of the Toroidal Rotation of the Bulk Ions at Textor by Rutherford Scattering

The Rutherford scattering diagnostic at TEXTOR was used to determine the central toroidal rotation speed of the hydrogenic bulk ions in the plasma. During neutral beam injection speeds of the order of 10(5) ms-1 were found. With balanced injection no rotation was observed. A first comparison with charge exchange recombination spectroscopy showed, within the accuracy of the methods, no difference in the derived speeds, in agreement with neoclassical theory. The momentum confinement time of the central hydrogenic ions was found to decrease with the neutral beam power as approximately 1/square-root P(NBI)

Resonant Coupling of Ion-Cyclotron Waves to Energetic Helium-Ions

First measurements were performed to test a model prediction which states that the off-axis coupling of ion-cyclotron waves to energetic helium ions can generate either an inward or an outward drift of these particles. Ion-cyclotron waves with a power or up to 1 MW are coupled to energetic particles at the high field side, the low field side, or in the center by varying the toroidal magnetic field. When changing the heating power or the resonance location, the variation of the concentration of the energetic helium in the plasma agrees qualitatively with the model predictions