Kinetic Modelling of CBET Mitigation Using Laser Bandwidth

ORAL

Abstract

In the context of direct-drive inertial confinement fusion (ICF), it has been acknowledged that the levels of cross-beam energy transfer (CBET) found in current experiments would likely preclude ignition in a full-scale shot[1]. In experiments on the OMEGA laser, CBET reduces laser-target coupling by up to 30\%[2], with even higher losses on the NIF[1]. Increased laser driver bandwidth offers a promising route to mitigate CBET and other laser-plasma instabilities, which would allow for a significant expansion of the ICF design space. Here we present VPIC[3] particle-in-cell simulations investigating the efficacy of bandwidth in reducing CBET. We compare the PIC results with linearized fluid simulations performed with the LPSE code[4] and discuss the significance of nonlinear kinetic and fluid effects and their response to bandwidth. [1] V. N. Goncharov et al. (2017). Plasma Physics and Controlled Fusion, 59(1), 014008. [2] I. V. Igumenshchev et al. (2010). Physics of Plasmas, 17(12), 21–26. [3] K. J. Bowers et al. (2008). Physics of Plasmas, 15(5), 055703. [4] J. F. Myatt et al. (2019). Journal of Computational Physics, 399, 108916.

*LANL work supported by ICF and LDRD Programs.

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Authors

  • A. G. Seaton

    • Los Alamos National Laboratory, Los Alamos NM, 87544

  • L. Yin

    • Los Alamos National Laboratory, Los Alamos NM, 87544
    • Los Alamos Natl Lab
    • Los Alamos National Laboratory

  • Russell Follett

    • University of Rochester
    • Laboratory for Laser Energetics, U. of Rochester
    • Laboratory for Laser Energetics, University of Rochester, Rochester, NY 14623
    • Laboratory for Laser Energetics

  • Ari Le

    • Los Alamos National Laboratory
    • Los Alamos National Laboratory, Los Alamos NM, 87544
    • Los Alamos Natl Lab

  • B. J. Albright

    • Los Alamos National Laboratory, Los Alamos NM, 87544
    • Los Alamos National Laboratory
    • LANL