Finite Larmor radius effects on the stability properties of internal modes of a Z-pinch

Abstract

From the Vlasov-fluid model a set of approximate stability equations describing the stability of a cylindrically symmetric z-pinch is derived. The equations are derived in the limit of small gyroradius and include first order kinetic effects such as finite ion Larmor radius effects and resonant ion effects. Neglecting the resonant ion terms, we explicitly solve this set of equations for a constant current density profile leading to a dispersion relation. FLR effects are shown for the case of m = 1 internal mode to be stabilizing and for large wavenumbers k, using a trial function approach, absolute stabilization is found.