Fishbone-like burst modes (FBs) and toroidal Alfven eigenmodes (TAEs) excit
ed by energetic ions were observed for the first time in CHS heliotron/tors
atron plasmas heated by co-injected neutral beams, where the rotational tra
nsform is increased by the induced beam driven current. FBs of m = 3/n = 2
(where m, n are the poloidal and toroidal mode numbers) induce a pulsed inc
rease in the energetic ion loss flux. FBs of m = 2/n = 1 induce sawtooth os
cillations in the latter half of a discharge where the plasma beta becomes
high. Only when the beam velocity exceeds about half of the central Alfven
velocity and the net plasma current is induced to the required level are TA
Es with n = 1 and n = 2 excited; these are localized in the plasma core reg
ion, where the magnetic shear is appreciably reduced by the net plasma curr
ent. So far, TAE induced energetic ion loss has not been observed.