Impact of ICRH heating of fast D and T ions on fusion performance in JET DTE2 campaign

This work studies the impact of the Ion Cyclotron Resonance Heating (ICRH) of the fast Neutral Beam Injected (NBI) D and T ions on the fusion performance in recent JET DTE2 campaign. The effect of the Radio Frequency (RF) wave on fast NBI D and T ion dynamics was analyzed by means of TRANSP simulations. Moderate increase, 5-10%, in DT reaction rates was predicted by TRANSP for the case of ICRH heating of fast NBI D ions at n=2 harmonic of ion cyclotron resonance. The simulations have shown that synergistic interaction between fast NBI T ions and RF waves have little or no impact on the fusion performance in the experimental conditions discussed here. Contribution of various heating and fast ion sources have been assessed and discussed. The absence of strong interaction between fast NBI T ions and RF waves was attributed to the poorer penetration of the T beams leading to lower fast T ion densities in the core and the lower perpendicular velocity of the fast NBI T ions resulting in diminished intensity of fast particle - RF wave interaction.