Bremsstrahlung emission modelling and application to fast electron physics

Measurements of fast electron bremsstrahlung (FEB) using hard X-ray (HXR) cameras provide a unique diagnostic for the fast electron dynamics, with resolution in space, time and energy. A synthetic HXR diagnostic is developed to calculate the distribution function and FEB emission, such that experimental results can be directly compared with simulations. Using this comparison, the role of fast electron radial transport in radio-frequency current drive is investigated. For two cases studied in this paper, the HXR emission is consistent with negligible radial transport, although in one case this is in disagreement with the measured driven current.