Fast-ion redistribution due to sawtooth crash in the TEXTOR tokamak measured by collective Thomson scattering

Here we present collective Thomson scattering measurements of 1D fast-ion distribution functions in neutral beam heated TEXTOR plasmas with oscillations. Up to 50% of the fast ions in the centre are redistributed a consequence of a sawtooth crash. We resolve various directions to the field. The fast-ion distribution is found to be anisotropic as expected. a resolved angle of 39¿ to the magnetic field we find a drop in the fast-ion of 20–40%. For a resolved angle of 83¿ to the magnetic field the is no larger than 20%.(Some figures in this article are in colour only in the electronic version)