Compatibility of Alfvén ion‐cyclotron and magnetohydrodynamic stability criteria for an axisymmetric magnetic mirror

The stability of an axisymmetric magnetic‐mirror cell surrounded by a conducting wall is studied using the sharp‐boundary model. Depending on the ion pressure model p(B), magnetohydrodynamic (MHD) stability can be achieved in certain ranges at either high or low β. Suppression of the Alfven ion‐cyclotron microinstability requires the mirror cell to be short (length≲20 ion Larmor radii). Adiabaticity of ion orbits is then found to be a constraint that is difficult to satisfy. Within the approximations used in this paper, satisfaction of all constraints is achieved in only a small region of parameter space.