Energetic Particle Effects on MHD Stability of a Tandem Mirror Plasma

Energetic particle effects on MHD stability of a tandem mirror plasma is studied theoretically. An algebraic dispersion equation with respect to eigenfrequency is derived from a radial eigenmode equation for flute-mode perturbations with an appropriate boundary condition, in which the effects of energetically drifting ions are taken into account. The dispersion equation describes interactions between curvature-driven interchange modes and drift modes driven by energetically drifting ions. In the absence of wave-particle interactions for energetically drifting ions, the dispersion equation is solved numerically, and a stable region formed due to the charge uncovering effects of energetically drifting ions is shown in a parameter space related with the number density and magnetic drift frequency of energetically drifting ions.