Bridging the Microscopic and Macroscopic Realms of Laser Driven Plasma Dynamics

Abstract

The physical processes shaping laser plasma dynamics take place on length scales ranging from the microscopic (1 ångström) to the macroscopic realms (µm). Microscopic field fluctuations due to the motions of individual plasma charges evolve on an atomic scale. Collisional effects influencing thermalization and ionization processes depend on the plasma fields on an atomic level. Simultaneously, collective processes such as plasma oscillations take place on a mesoscopic length scale of many-nm. The macroscopic realm is ultimately determined by the laser which typically spans hundreds of nm to a few µm. Consequently, ab-initio modelling of laser plasma dynamics requires the resolution of length scales from 1Å to multiple µm. As such, in order to bridge the microscopic and macroscopic length scales of light-matter interaction, in is necessary to account for the individual motions of up to ~10^11 particles. This is a not an insignificant undertaking. Until recently, approaches to numerical modelling of light-matter interactions were limited to MD and PIC, each with their own limitations. MicPIC has been developed to fill the gap left by MD and PIC but so far has not been adapted for scalable parallel processing on large distributed memory machines. Thus, its full potential was not able to be fully realized until now. This thesis presents the massively parallel MicPIC method capable of bridging the micro- and macroscopic realms. A wide range of applications that have heretofore not been accessible to theory or, at best, had limited applicability are now open for thorough investigation. Among these are nonlinear nanophotonics, quantum nanophotonics, laser machining, ab-initio dynamics of strongly coupled plasmas, high-harmonic generation, electron and x-ray sources, and optical switching. Two of the first applications of parallel MicPIC to a selection of such problems are shown and discussed below, demonstrating the applicability of the method to a wide variety of newly accessible strong field laser-plasma physics phenomena.