Effects on Doppler Profiles in Beam-Heated Plasmas

摘要

We analyze various effects that can influence ion temperature measurements based on Doppler broadening of impurity lines. Macroscopic effects such as inhomogeneities, plasma rotation and temporal modulations are distinguished from microscopic ones leading to species-dependent temperatures and anisotropy in the impurity distribution functions. There are turbulent effects related to the latter that can also cause deviations from thermodynamic equilibrium among light and heavy impurities. It is found that under neutral-beam-heated JET conditions, all effects should be small and influence the measured ion temperature by less than approx. 10%. Larger influences could be expected from strongly peaked rotation profiles - for which, however, no indications are found - and high-level turbulence, which appears rather unrealistic, too. (ERA citation 13:047939)