Measurements of plasma ion temperature and rotation velocity using the He II 4686-Å line produced by charge transfer

Abstract

Spatially and temporally resolved values of the ion temperature and toroidal rotation velocity near the plasma axis have been obtained in neutral beam-heated plasmas in the Doublet III tokamak from measurements of the Doppler broadening and Doppler shift of the He II 4686-Å line, excited by charge transfer reactions between fast hydrogen atoms in the beam and thermal helium ions in the plasma. The measurement technique, which uses visible optics and a multichannel detector, promises to be a straightforward method to obtain ion temperature profiles in beam-heated tokamaks.