Comprehensive magnetized collisionless shock observations with deep learning aided diagnostic analysis

ORAL  · Invited

Abstract

Collisionless shocks are of great interest to the astrophysics community due to their prevalence throughout astrophysics phenomena, including supernova remnants and planetary bow shocks, and candidacy for particle accelerators of cosmic rays. Despite their ubiquity, key formation and sustentation processes of collisionless shocks are still not fully understood. Laboratory experiments have become a valuable tool to further study these systems in controllable and repeatable conditions. Furthermore, the improvements to and growing accessibility of high repetition rate experiment capabilities potentially offer unparalleled insight into system evolution, but the dynamicity and sheer size of these datasets could render conventional analysis challenging. In this work we demonstrate how deep learning models could serve as potential candidates to help meet the needs of future experiments.

We present results from experimental campaigns at the OMEGA laser facility to study quasi-perpendicular (Tubman et al., in preparation) and quasi-parallel shock formation and highlight how optical Thomson scattering (OTS) is used to measure key plasma parameters to better understand and detect shock formation. Results are compared with particle-in-cell simulations. We then demonstrate how deep learning models can be trained to accelerate and aid OTS analysis by predicting plasma conditions directly from OTS spectra (Pokornik et al., Phys. Plasmas 31, 7 2024) collected from both experimental campaigns and theoretical spectra forward modeled from simulations. We discuss the advantages and limitations of the models and present preliminary work on predicting fully arbitrary particle velocity distributions.

*This material is based upon work supported by the National Nuclear Security Administration, Stewardship Science Academic Alliances, under Award Number DE-NA0004147. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344

Publication: 1E. R. Tubman, M. Pokornik, C. J. Bruulsema, R. S. Dorst, F. Fiuza, D. P. Higginson, D. J. Larson, M. J.-E. Manuel, K. Moczulski, B. B. Pollock, J. S. Ross, G. F. Swadling, P. Tzeferacos, H. -S. Park. "Observation of ion reflection and shock separation in supercritical, laser-driven, magnetized collisionless conditions", in preparation
2Pokornik, M., Higginson, D. P., Swadling, G., Larson, D., Moczulski, K., Pollock, B., Tubman, E., Tzeferacos, P., Park, H. S., Beg, F., Arefiev, A., & Manuel, M. (2024). "A deep learning approach to fast analysis of collective Thomson scattering spectra" Physics of Plasmas, 31(7), 072115. https://doi.org/10.1063/5.0201148
3M. Pokornik, R.S. Dorst, E. R. Tubman, C. J. Bruulsema, D.P. Higginson, G. Swadling, D. Larson, M. Manuel, S. Bolaños, B. Pollock, K. Moczulski, P. Tzeferacos, T. Bachmann, F. Fuiza, H. -S. Park, F. Beg, A. Arefiev. "Predicting arbitrary particle velocity distribution functions from Thomson scattering spectra"

Presenters

  • Michael Pokornik

    • University of California San Diego

Authors

  • Michael Pokornik

    • University of California San Diego
  • Robert S Dorst

    • Lawrence Livermore National Laboratory
  • Eleanor Tubman

    • University of California, Berkeley
  • Colin J Bruulsema

    • Lawrence Livermore National Laboratory
  • Drew P Higginson

    • Lawrence Livermore National Laboratory
  • George F Swadling

    • Lawrence Livermore National Laboratory
  • David Jeffrey Larson

    • Lawrence Livermore National Laboratory
  • Mario J Manuel

    • General Atomics
  • Simon Bolaños

    • University of California, San Diego
  • Kassie Moczulski

    • University of Rochester
  • Petros Tzeferacos

    • University of Rochester
  • Tristan Bachmann

    • University of Rochester
  • Frederico Fiuza

    • Instituto Superior Tecnico
  • Hye-Sook Park

    • Lawrence Livermore National Laboratory
  • Farhat N Beg

    • University of California, San Diego
  • Alexey Arefiev

    • University of California, San Diego