Numerical Analysis of ICRF Minority Heating in Helitoron J

抄録

The effect of the magnetic configuration on fast-ion confinement is one of the most important topics for helical devices. Fast-ion velocity distributions have been investigated using ion cyclotron range of frequencies (ICRF) minority heating in Heliotron J with special emphasis on the effect of the toroidal ripple (bumpiness) of the magnetic field strength. In measurements of the fast-ion tail generated by ICRF minority heating, a high bumpiness configuration is found to be preferable for tail formation. However, the measurement area based on the line of sight of the fast-ion detector was restricted in this experiment. Due to the complexity of the magnetic field in Heliotron J, three-dimensional analysis is required to interpret the experimental results. Monte-Carlo simulations were performed. The calculation results agree well with the experimental results for high-energy tail formation. The effective temperature of minority protons was estimated.