Measurement of the Energetic Particle in NBI Plasmas of Heliotron J

The behavior of energetic particles is investigated with a charge-exchange neutral particle energy analyzer (CX-NPA) system in Heliotron J. In the tangential neutral beam injection (NBI) experiments, the high energy tail component up to 20keV is observed in proton energy spectrum. The dependence of the energetic particle confinement on the magnetic configuration is studied with regard to one of the Fourier spectrum of the mag- netic field, bumpiness. The decay time of CX-flux after the termination of NBI decreases with increasing the bumpiness component.