2D Kinetic Particle in Cell Simulations of a Flow-Shear Stabilized Z-Pinch*

The lifetime of Z-pinch plasmas is typically limited by MHD instabilities, e.g. the m = 0 “sausage” and m = 1 “kink” modes. An attractive strategy to suppress these and related instabilities and extend the lifetime of a Z-pinch is to drive sheared axial flows in the plasma, $dv_{z}/dr \neq 0$. This stabilization was demonstrated in a series of experiments at the UW and these long-lived Z-pinches may offer viable sources of ion beams, neutrons and radiation, or potentially, a fusion reactor. LLNL is running 2D simulations using the particle-in-cell(PIC) code, LSP, to study flow-shear Z-pinch stability and performance. The suppression of the sausage mode by axial flow-shear is seen under the present experimental conditions as well as at reactor scales, with multiple shear-flow profiles. The longevity of these sheared-flows depends on the plasma viscosity, and a preliminary viscosity and shear-flow longevity analysis is also presented. This work represents the first fully-kinetic modeling results for the flow-shear stabilized Z-pinch.