Vlasov fluid stability of the m=0 mode in a skin current Z pinch

Abstract

The m=0 stability of a Z pinch confined by a skin current has been studied using the Vlasov fluid model. A significant reduction in growth rate compared to ideal magnetohydrodynamics (MHD) is found. An exact analytic solution can be obtained at large ka (k is the axial wavenumber and a is the pinch radius). In this limit the Vlasov fluid growth rate (normalized to the radial ion thermal transit time) saturates to the value 0.5 (π)1/2, in contrast to the ideal MHD growth rate, which increases without limit as (k)1/2.