Design of Meter-Scale Laser Wakefield Accelerators

Laser-plasma acceleration of electrons, which is characterized by ultra-high gradients, offers the promise of reducing the cost and size of next-generation electron linacs. Simulations have played a key role in understanding this phenomenon, but more than a million processor hours are required to accurately simulate even 1 GeV of acceleration. 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. The technique of modeling the laser field by its envelope, rather than using explicit fields, eliminates the need to resolve the laser wavelength, allowing lower resolution and larger time steps. Orders of magnitude speedup have been demonstrated with this technique. This project will implement the additional features necessary to extend these envelope-modeling simulations to full meter-scale experiments. The simulation results will be compared to those for explicit PIC and validated via comparison with experimental data. Commercial Applications and other Benefits as described by the awardee The proposed approach to speeding up laser-plasma PIC and fluid simulations should benefit DOE funded researchers and other institutions. The plasma-based electron accelerators that would be simulated with this technique show increasing promise for next-generation high-energy electron linacs and high-brightness ion sources. Such accelerators are also candidates for compact light sources in the X-ray and THz regimes, with many applications in medicine, science, and national security