Collaborative Research: Vlasov Multi-Dimensional Simulation of Langmuir Wave Collapse and Stimulated Raman Scatter in the Fluid-Kinetic Transition Regime

University Of New Mexico, Albuquerque NM

Investigators

Abstract

This award enables development and application of the Vlasov Multi-Dimensional (VMD) model to fundamental phenomena in non-equilibrium plasma dynamics. The VMD model takes advantage of directed plasma wave turbulence properties, encountered in laboratory and space environments, by rigorously joining particle and fluid aspects of plasma dynamics, something which has previously been unattainable. It had been thought that models which explicitly incorporate fluid dynamics must omit essential aspects of high temperature plasma dynamics. By showing that this is not necessarily the case, the VMD model advances our understanding, showing what is and what is not essential in standard plasma models. VMD results in vastly more efficient simulation methods than afforded by traditional PIC ("particle in cell") methods. An early research goal is validation of the VMD model by comparison with results previously obtained by PIC simulations. Validation of the VMD model will allow its application to predicting the nonlinear evolution of plasma waves that naturally occur in high temperature plasma as found in the neighborhood of pulsars, in the earth's ionosphere, and, closer to earth, as they occur in the propagation of intense microwave and laser pulses in laboratory generated plasma. Of particular importance is the more accurate modeling of regime change. For example, how much power can be transmitted before plasma wave turbulence blocks laser propagation? Determination of laser intensity at regime change boundaries by PIC simulation may be obscured by unphysical noise. The VMD method is noise free, expanding the scope of plasma dynamics accessible by simulation.