Electric field induced loss cone study by the charge exchange energy spectrum

The charge exchange energy spectrum of beam ions is analyzed in order to study the fast ion confinement. The spectrum is observed to have a depletion, and the effects of the magnetic field, B0 and radial electric field, Er, induced losses on the depletion structures are discussed. Relaxation oscillations of the spectrum are found and a time varying Er is considered to interpret them. A reduction of the depletion structure is observed with electron cyclotron resonance heating (ECRH), and is discussed with the edge Er change and improved ion heating.