Monte Carlo simulations of edge ion temperature profile in ASDEX Upgrade
ABSTRACT The possibility of using the low energy channels of neutral particle analyzers to measure edge ion temperature profile in tokamaks has been investigated. The perpendicular velocity distribution of the edge ions has been simulated for an H-mode ASDEX Upgrade discharge using the guiding center orbit following Monte Carlo code ASCOT. The local temperatures extracted from the simulation by assuming a local Maxwellian distribution are within 10% of the background temperature. More simulations with wider radial extent and longer simulation times axe required in order to determine if the small discrepancy is due to boundary effects, incomplete filling of the velocity space, or a non-Maxwellian nature of the ion distribution function. When the ion temperature profile is made very steep, the non-Maxwellian nature of the distribution does emerge already in these simulations.