In preparation for next step burning plasma devices such as ITER, experimental studies of instabilities and confinement of energetic ions were performed on Joint European Torus (JET) and on Mega-Amper Spherical Tokamak (MAST) with innovative diagnostic techniques, in conventional and shear-reversed plasmas, exploring a wide range of effects for energetic ions. A compendium of recent results testing capabilities of the present-day facilities for burning plasma relevant study is presented in this paper. ‘Alpha tail’ production using 3rd harmonic ion-cyclotron resonance heating (ICRH) of 4He beam ions has been employed on JET for studying 4He of the megaelectronvolt energy range in a ‘neutron-free’ environment. The evolution of ICRH-accelerated ions of 4He with E
1.7MeV and D with E
500 keV was assessed from nuclear gamma-ray emission born by the fast ions colliding with Be and C impurities. A simultaneous measurement of spatial profiles of fast 4He and fast D ions relevant to ITER was performed for the first time in positive and strongly reversed magnetic shear discharges. Time-resolved gamma-ray diagnostics for ICRH-accelerated 3He and H minority ions allowed changes in the fast ion distribution function to be assessed in the presence of unstable toroidal Alfv´en eigenmodes (TAEs) and sawteeth.