Minority heating by ICRH: a tool for investigating burning plasma physics in FAST

A combined Fokker–Planck numerical analysis of the quasi-linear plasma–ion-cyclotron (IC) wave interaction and collisional relaxation of minority ion tails created by IC absorption was performed in order to determine the characteristic fast-ion parameters that are necessary for addressing some of the main ITER burning plasma physics issues, e.g. fast-ion transport due to collective mode excitations, cross-scale couplings of micro-turbulence with meso-scale fluctuations due to energetic particles, etc. These investigations refer to actual scenarios of the Fusion Advanced Studies Torus (FAST), a conceptual tokamak design operating with deuterium plasmas in a dimensionless parameter range similar to that of ITER and equipped with IC resonance heating (ICRH) as a main heating scheme. The destabilization and saturation of fast-ion driven Alfvénic modes below and above the energetic particle modes stability threshold are investigated by numerical simulations with the HMGC code, which assumes the anisotropic energetic particle distribution function accelerated by ICRH as input. The results of this study, obtained by integration of different numerical simulation analyses aimed at investigating the various relevant physics, are presented and discussed.