Study of Ion Cyclotron Emissions due to DD Fusion Product Ions on JT-60U

In this paper, ion cyclotron emissions (ICEs) due to deuterium-deuterium (DD) fusion-product (FP) He, T and P-ions on JT-60U are described. Electromagnetic waves with finite toroidal wave numbers are detected by using ion cyclotron range of frequency antennas as pickup loops. The toroidal wave numbers are evaluated from the phase differences between two antenna straps arrayed in the toroidal direction. The excitation of the fast Alfvén waves for the mechanism of ICEs due to He and P-ions, ICE(He) and ICE(P), is consistent with that in the previous JET and TFTR experiments. ICE due to T-ions, ICE(T), with lower frequency has larger wave numbers than ICE(He). The excitation of the slow Alfvén waves is elucidated for the first time as the mechanism for ICE(T). The density dependence for the excitation of the fundamental and the second harmonic ICEs(He) is obtained. The fundamental ICE(He) appears only in relatively low density operation. A frequency peak due to FP-ions sometimes splits into a doublet shape as observed in JET experiments. The phase differences of both peaks are detected to be positive and negative values and indicate that two waves are traveling in both toroidal directions. The anisotropy of the FP T-ions at the outer plasma edge is evaluated by using ‘Escape Particle Orbit analysis Code (EPOC)’. The precise behaviors of ICEs due to FP-ions on JT-60U are studied.