Kinetic stability of the finite electron temperatureZ-pinch

Abstract

Large Larmor radius (LLR) stability of linear m = 0 and m = 1 modes in a Z-pinch has been studied using the Vlasov-fluid model (Arber et al 1994 Phys. Rev. Lett. 72 2399 Phys. Rev. Lett. 74 2698. Ions have been modelled fully kinetically through the Vlasov equation, and electrons are treated as a zero temperature, massless fluid. In the present work an improved Vlasov-fluid model is used to investigate the effect of finite electron temperature on m = 0 modes. An electron energy equation is introduced, and results for both adiabatic and isothermal dynamics are presented. It is found that finite electron temperature has a destabilizing effect in general. As a result, the Z-pinch is only weakly stabilized by LLR effects.

The physics of fastZpinches

“…The growth rate is reduced by a factor of 2-3 with respect to an ideal MHD, but this is insufficient for a long-lasting steady-state equilibrium. Scheffel et al (1997) have shown that a finite electron temperature has a destabilizing effect on a plasma with a finite Larmor radius.…”

The physics of fast Z pinches

“…The growth rate is reduced by a factor of a few with respect to an ideal MHD, but this is insufficient to have a long-lasting steady-state equilibrium. Scheffel et al (1997) have shown that the effects of a finite electron temperature have a destabilizing effect on the finite Larmor radius plasma.…”