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Title: Characteristics of an envelope model for laser-plasma accelerator simulation

Abstract

Simulation of laser-plasma accelerator (LPA) experiments is computationally intensive due to the disparate length scales involved. Current experiments extend hundreds of laser wavelengths transversely and many thousands in the propagation direction, making explicit PIC simulations enormously expensive and requiring massively parallel execution in 3D. Simulating the next generation of LPA experiments is expected to increase the computational requirements yet further, by a factor of 1000. We can substantially improve the performance of LPA simulations by modeling the envelope evolution of the laser field rather than the field itself. This allows for much coarser grids, since we need only resolve the plasma wavelength and not the laser wavelength, and therefore larger timesteps can be used. Thus an envelope model can result in savings of several orders of magnitude in computational resources. By propagating the laser envelope in a Galilean frame moving at the speed of light, dispersive errors can be avoided and simulations over long distances become possible. The primary limitation to this envelope model is when the laser pulse develops large frequency shifts, and thus the slowly-varying envelope assumption is no longer valid. Here we describe the model and its implementation, and show rigorous benchmarks for the algorithm, establishing second-ordermore » convergence and correct laser group velocity. We also demonstrate simulations of LPA phenomena such as self-focusing and meter-scale acceleration stages using the model.« less

Authors:
 [1];  [2];  [1]
  1. Tech-X Corporation, Boulder, CO 80303 (United States)
  2. LOASIS Program, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)
Publication Date:
OSTI Identifier:
21499740
Resource Type:
Journal Article
Journal Name:
Journal of Computational Physics
Additional Journal Information:
Journal Volume: 230; Journal Issue: 1; Other Information: DOI: 10.1016/j.jcp.2010.09.009; PII: S0021-9991(10)00503-6; Copyright (c) 2010 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Journal ID: ISSN 0021-9991
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ALGORITHMS; CONVERGENCE; EVOLUTION; FOCUSING; LASER RADIATION; LASERS; PLASMA; PLASMA ACCELERATION; PLASMA GUNS; PLASMA SIMULATION; PULSES; WAVELENGTHS; ACCELERATION; ELECTROMAGNETIC RADIATION; MATHEMATICAL LOGIC; RADIATIONS; SIMULATION

Citation Formats

Cowan, Benjamin M., E-mail: benc@txcorp.co, Bruhwiler, David L., E-mail: bruhwile@txcorp.co, Cormier-Michel, Estelle, LOASIS Program, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, Esarey, Eric, Geddes, Cameron G.R., E-mail: CGRGeddes@lbl.go, Messmer, Peter, and Paul, Kevin M., E-mail: kpaul@txcorp.co. Characteristics of an envelope model for laser-plasma accelerator simulation. United States: N. p., 2011. Web. doi:10.1016/j.jcp.2010.09.009.
Cowan, Benjamin M., E-mail: benc@txcorp.co, Bruhwiler, David L., E-mail: bruhwile@txcorp.co, Cormier-Michel, Estelle, LOASIS Program, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, Esarey, Eric, Geddes, Cameron G.R., E-mail: CGRGeddes@lbl.go, Messmer, Peter, & Paul, Kevin M., E-mail: kpaul@txcorp.co. Characteristics of an envelope model for laser-plasma accelerator simulation. United States. https://doi.org/10.1016/j.jcp.2010.09.009
Cowan, Benjamin M., E-mail: benc@txcorp.co, Bruhwiler, David L., E-mail: bruhwile@txcorp.co, Cormier-Michel, Estelle, LOASIS Program, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, Esarey, Eric, Geddes, Cameron G.R., E-mail: CGRGeddes@lbl.go, Messmer, Peter, and Paul, Kevin M., E-mail: kpaul@txcorp.co. 2011. "Characteristics of an envelope model for laser-plasma accelerator simulation". United States. https://doi.org/10.1016/j.jcp.2010.09.009.
@article{osti_21499740,
title = {Characteristics of an envelope model for laser-plasma accelerator simulation},
author = {Cowan, Benjamin M., E-mail: benc@txcorp.co and Bruhwiler, David L., E-mail: bruhwile@txcorp.co and Cormier-Michel, Estelle and LOASIS Program, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 and Esarey, Eric and Geddes, Cameron G.R., E-mail: CGRGeddes@lbl.go and Messmer, Peter and Paul, Kevin M., E-mail: kpaul@txcorp.co},
abstractNote = {Simulation of laser-plasma accelerator (LPA) experiments is computationally intensive due to the disparate length scales involved. Current experiments extend hundreds of laser wavelengths transversely and many thousands in the propagation direction, making explicit PIC simulations enormously expensive and requiring massively parallel execution in 3D. Simulating the next generation of LPA experiments is expected to increase the computational requirements yet further, by a factor of 1000. We can substantially improve the performance of LPA simulations by modeling the envelope evolution of the laser field rather than the field itself. This allows for much coarser grids, since we need only resolve the plasma wavelength and not the laser wavelength, and therefore larger timesteps can be used. Thus an envelope model can result in savings of several orders of magnitude in computational resources. By propagating the laser envelope in a Galilean frame moving at the speed of light, dispersive errors can be avoided and simulations over long distances become possible. The primary limitation to this envelope model is when the laser pulse develops large frequency shifts, and thus the slowly-varying envelope assumption is no longer valid. Here we describe the model and its implementation, and show rigorous benchmarks for the algorithm, establishing second-order convergence and correct laser group velocity. We also demonstrate simulations of LPA phenomena such as self-focusing and meter-scale acceleration stages using the model.},
doi = {10.1016/j.jcp.2010.09.009},
url = {https://www.osti.gov/biblio/21499740}, journal = {Journal of Computational Physics},
issn = {0021-9991},
number = 1,
volume = 230,
place = {United States},
year = {2011},
month = {1}
}