Ion Cyclotron Resonant Heating in the Central Cell of the Keda Mirror with AXisymmetricity (KMAX)

We report the results of ion cyclotron resonance heating (ICRH) in the central cell of a fully axisymmetric tandem mirror. With a total power of 100 kW radiated by double half-turn (DHT) and half-turn (HT) antennas, the plasma diamagnetism increases by 15-fold, with a corresponding peak  beta ~2%, density ~ 2*10^18 m^-3 , and total temperature ~60 eV. The effects of the magnetic configuration on resonance heating and wave emission are studied by varying the magnetic fields at the midplane and at the location of the antennas, respectively; the results confirm that the magnetic beach configuration is key to successful ICRF heating. The axial phase speed measurements suggest that the excited wave is a slow wave in the plasma core and a fast wave at the edge.