Conducting-wall and pressure profile effect on MHD stabilization of axisymmetric mirror

The MHD energy principle is used to examine the stabilization effect of a conducting wall located near the plasma surface. The stabilization effect is maximized when the normal component of the perturbed magnetic field approaches zero (Q n = 0) at the plasma surface. Under this boundary condition, the eigen-equation of the plasma displacement is solved for a two-step flat pressure profile model, which can include both a non-hollow and a hollow pressure profile. Only the rigid m = 1 mode is considered due to the finite-Larmor-radius effect. For an isotropic pressure component, it is found that a hollow profile has better stability than a uniform pressure when the integral of the radial pressure profile is fixed. Implications for plasma experiments and fusion reactors are discussed.