Observation of Fast Ion Tail Using Neutral Particle Analyzer in C-2W

In C-2U experiments, thermal ion acceleration by a beam-driven wave was observed [1]. This thermal ion acceleration is pointed out to dramatically enhance the fusion rate because the beam energy is transferred to thermal ions, bypassing the electron channel and related loss mechanisms.

The C-2W device has achieved higher plasma parameters than its predecessor (pressure, stored energy) [2]. In experiments with mixed hydrogen and deuterium beam injection, a neutral particle analyzer [3] has observed acceleration of deuterons well beyond the neutral beam energy. When the bulk plasma parameters are similar, the effective temperature of the fast deuterium ion tail is correlated with the amplitude of microburst [4] suggesting that the deuteron ions may be directly accelerated by the beam-driven wave.