Designing 1-100 GeV Laser-Plasma Accelerators in an Optimal Lorentz Frame

Laser-plasma acceleration of electrons, characterized by ultra-high gradients, has shown promise for reducing the cost and size of next-generation electron linacs. For example, GeV electron bunches have been obtained in a 3 cm plasma channel, suggesting the possibility of demonstrating 10 and even 100 GeV beams. Simulations have played a key role in supporting these efforts, but more than a million processor hours are required to accurately simulate even 1 GeV of acceleration. Therefore, simulation run-time must be reduced by many orders of magnitude, so that present experiments can be accurately analyzed and future experiments can be designed in advance. Time-explicit particle-in-cell (PIC) and fluid simulations provide the most complete description of the laser-plasma interaction and electron acceleration, but the enormous ratio of interaction time to laser oscillation period makes this approach unacceptably slow. In order to reduce this ratio by orders of magnitude, this project will conduct simulations in an optimally chosen Lorentz frame, without making any of the approximations required by ponderomotive guiding centers or quasi-static algorithms. Simulation results will be validated via comparison with experimental data. Commercial Applications and other Benefits as described by the awardee: GeV-scale plasma-based electron accelerators show increasing promise for next-generation high energy electron linacs, and also as high-brightness ion sources. Such accelerators also would be candidates for compact ¿light sources¿ in the x-ray regime (via synchrotron radiation and Compton backscatter) and the THz regime (via coherent transition radiation), with many applications in medicine, science and national security. The enhanced parallel simulation code would be made available to DOE funded researchers and other institutions under appropriate commercial and non-commercial licenses.