Alfven mode induced particle loss in LHD

Losses of beam ions due to Alfven modes are simulated for discharges in the Large Helical Device at Toki, Japan, using a guiding center code. High frequency beam particle resonances are found for the equilibria for passing particles, providing locations for the destablization of Alfven modes observed in the device. Losses due to even small modes due to these resonances are significant.