Flow effects on the stability of z-pinches
- Phillips Lab., Kirtland AFB, NM (United States)
- Lawrence Livermore National Lab., CA (United States)
The effect of an axial flow on the m = 1 kink instability in z-pinches is studied numerically by reducing the linearized ideal MHD equations to a one-dimensional eigenvalue equation for the radial displacement. The derivation of the displacement equation for equilibria with axial flows will be presented. A diffuse z-pinch equilibrium is chosen that is made marginally stable to the m = 0 sausage mode by tailoring the pressure profile. The principle result reveals that a sheared axial flow does stabilize the kink mode when the shear exceeds a threshold value. Additionally, the m = 0 sausage mode is driven from marginal stability into the stable regime which suggests that the equilibrium pressure profile control can be relaxed. Fast z-pinches such as liner implosions are plagued by the Rayleigh-Taylor instability which destroys the liner and disrupts the current path before the liner arrives on axis. A sheared axial flow in a liner may quench the Rayleigh-Taylor instability in the same way that it quenches MHD instabilities in a diffuse z-pinch. Simulation results will be presented showing the effect of a sheared axial flow on the Rayleigh-Taylor instability in a fast liner implosion.
- OSTI ID:
- 419793
- Report Number(s):
- CONF-960634--
- Country of Publication:
- United States
- Language:
- English
Similar Records
Sheared flow stabilization of the {ital m}=1 kink mode in {ital Z} pinches
2D MHD simulations of Rayleigh-Taylor instability in Z-pinches