Microstability of the TARA axicell

Potential enhancement in the axicell of TARA can accrue from either generation of a thermal barrier or from electron pumping. The latter scheme can involve important changes in the axicell, including a reduction in the mirror ratio, the perpendicular injection of neutral beams, and a magnetic field which is not symmetric about the midplane. Numerical results will be presented showing the effect of these changes on ion loss-cone instabilities, using a new vectorized axial eligenmode code whose speed allows a broader range of parameters and equilibria to be examined than was practical previously