OVERVIEW OF FAST PARTICLE EXPERIMENTS IN THE FIRST MAST-U EXPERIMENTAL CAMPAIGNS
MAST-U is equipped with on-axis and off-axis neutral beam injectors (NBI), external sources of super-Alfvénic fast-ions that provide opportunities for studying a wide range of phenomena relevant to the physics of alpha-particles in burning plasmas. Clear evidence of fast-ion redistribution and loss due to sawteeth (ST), fishbones (FB), long-lived modes (LLM), Toroidal Alfvén Eigenmodes (TAE), Edge Localised Modes (ELM) and neoclassical tearing modes (NTM) has been found in results from a Neutron Camera (NCU) [1], a scintillator-based Fast-Ion Loss Detector (FILD) [2], a Solid-State Neutral Particle Analyser (SSNPA) [3] and a Fast-Ion Deuterium-Alpha (FIDA) spectrometer [4]. Unprecedented FILD measurements in the range 1 – 2 MHz suggest that fast-ion losses are induced by compressional or global Alfvén eigenmodes (CAEs or GAEs). Previous ASCOT simulations predicted that more than 20% of the fast-ion power could be lost due to charge exchange (CX) losses. Dedicated experiments employing low field side (LFS) gas fuelling show a significant drop in NCU fluxes, providing additional evidence of CX-induced fast-ion losses. Simulations of LLM with the MARS-F code [5] predict co-current fast-ion losses on the low field side (LFS) midplane, in agreement with FILD measurements.