Energetic ion behaviour in MAST

Abstract

Recent studies of fast ion transport resulting from a range of instabilities, including n = 1 internal kink modes (fishbones and long-lived modes), toroidal Alfvén eigenmodes and sawteeth have been carried out at MAST. Strong correlations were found between relative changes in magnetic edge coils signals, edge Dα signal a fast ion Dα system, a prototype collimated neutron flux monitor and a recently installed prototype charged fusion product detector array, indicating both redistribution and loss of fast ions. Preliminary interpretation of these observations with a suite of stability, modelling and interpretative codes is discussed.