LBNL, Berkeley, California, USA
Numerical modeling of laser-plasma accelerators using the ponderomotive approximation allows efficient modeling of 10 GeV and beyond laser-plasma accelerators. The time-averaged ponderomotive force approximation also allows simulation in cylindrical geometry which captures relevant 3D physics at 2D computational cost. In this talk I will present the code INF&RNO (INtegrated Fluid & paRticle simulatioN cOde). The code is based on an envelope model for the laser while either a PIC or a fluid description can be used for the plasma. The effect of the laser pulse on the plasma is modeled with the time-averaged poderomotive force. These and other features, such as dynamical resampling of the phase space distribution to reduce on-axis noise and boosted-Lorentz-frame modeling capability, allow for a speedup of several orders of magnitude compared to standard full PIC simulations while still retaining physical fidelity. The code has been benchmarked against analytical solutions and 3D PIC simulations and a set of validation tests together with a discussion of the performances will be presented. Applications to the BELLA PW laser-plasma accelerator experiments at LBNL will be discussed.
LBNL, Berkeley, California, USA
LLNL, Livermore, California, USA
The Particle-In-Cell Code-Framework Warp originated in the Heavy Ion Fusion program to guide the development of accelerators that can deliver beams suitable for implosion of inertial fusion capsules. The range of application of Warp has considerably widened far beyond the initial area and it is now applied to the study and design of existing and next-generation high-energy accelerators, including, for example, the study of laser wakefield acceleration and electron cloud effects. We present an overview of Warp's capabilities, summarizing recent original numerical methods that were developed to address computational challenges such as space and time scale disparities, spurious numerical dispersion, efficient wideband digital filtering on parallel platforms, etc. The original methods include simulations in Lorentz boosted frames, an electromagnetic solver with tunable numerical dispersion and efficient stride-based digital filtering, Particle-In-Cell with Adaptive Mesh Refinement, a large-timestep ‘‘drift-Lorentz'' mover for arbitrarily magnetized species, and a relativistic Lorentz invariant leapfrog particle pusher. Selected examples of applications will be given.