PPPS-2013: The physics of KEEN waves and their interactions

Abstract

Summary form only given. The physics of kinetic electrostatic electron nonlinear (KEEN) waves is elucidated by detailed diagnoses of Vlasov-Poisson simulations. Here we explain the scaling of the multimode non-stationary density response and the phase space partitioned dynamics as a function of drive amplitude and using long time simulations with increasing velocity resolution. In addition, by using 2x-2v simulations, two-dimensional KEEN waves are driven and shown to retain their character found in 1x-1v simulations. Different transverse widths of ponderomotive drive will be compared. Also, Lenard-Bernstein collisions are included to show that the general features of phase space partition and multimode phase locked response both persist but now with a weakly decaying amplitude in time. Thus, this work proves the robustness of KEEN wave results found previously and extends them in dimension and with the addition of velocity space collisions.KEEN-KEEN and KEEN-EPW (electron plasma wave) interactions are considered with novel resonances involving multiple harmonics of KEEN wave interacting simultaneously with an EPW at resonance. This disallows EPW trapped particle states. But at different frequency ratios, their interactions are non-resonant and they are shown to be able to coexist. These are nonlocal interactions in phase space mediated by a common, self-consistent, nonstationary, multimode electrostatic field.