This award supports a project focusing on the development of novel multi-physics simulation tools suitable for detailed studies of phase-space dynamics of plasmas. These tools will be used to optimize the generation of high-quality multi-GeV electron beams by laser-plasma devices. Clear and complete understanding of phase-space processes opens the door to the manipulation of phase space and to greater control over high-energy-density-physics phenomena. Many of the technological applications of intense-laser plasma interactions, such as compact, next-generation light sources, have stringent limits on beam quality that exceed what is currently available. The results of this study are expected to advance the development of these technologies, having ultimate applications in a wide range of fields. The main problem to be addressed is that the existing theoretical understanding of the processes leading to trapped particles in large amplitude plasma waves driven by intense lasers, as seen in various experiments, is incomplete. To improve this, a phase-space level understanding of the mechanisms at work is essential. Current experiments typically rely on the free evolution of the laser-plasma system, i.e., a laser pulse is brought to a target and the system is allowed to evolve without subsequent intervention. Recent experimental results provide a tantalizing glimpse of the great promise of tailoring phase space to produce exploitable features. Realizing these advances requires a first principles understanding of the phase-space dynamics of these systems.
High energy density physics is coming to prominence as a new physics frontier; fully ionized matter (plasma) under extreme conditions is a source of exciting new physics. The advent of sub-picosecond, petawatt-class lasers opens a new chapter in ultrafast physics of relativistic laser plasma interactions. Centimeter-long relativistic plasmas are now being produced, and new, poorly understood phenomena are being observed. This makes the development of new theoretical frameworks and computational approaches essential. A combination of experimental and theoretical research is leading to new understanding of the complex plasma processes that can occur and will no doubt have significant practical applications to medicine, structural stability/safety, and homeland security. The results of the proposed research will be disseminated widely. The entire computational data set produced during this project will be archived and made publicly available through a web-based interface. Visitors to the archive can search the database, examine any of the data sets, create visualizations of the data, perform various diagnostics on the data sets as well as download raw data. The computer codes developed during this project will generally be made publicly available. Additionally all of the algorithms and their implementations, including full source code documentation, will be made publicly available on the PI's research group's web site. Integration of this research with education will be accomplished through motivation and improved teaching of undergraduate and graduate students. High school students from underrepresented groups also will be recruited to participate in summer research projects.