Bayesian inferences of radial current losses and symmetry in multi-terawatt magnetically insulated transmission lines via photonic doppler velocimetry

ORAL

Abstract

Assessments of the electrical current delivered by 20-30 MA pulsed power facilities has historically been enabled by bdot measurements at large-radius and at a limited number of azimuthal locations [1]. This sparsity, and that bdot data is unreliable for some configurations [2] precludes realizing the full design potential of sophisticated (but under-constrained) particle-in-cell simulations, and slows efforts to optimize magnetically insulated transmission line geometries. Relying on the Z machine at Sandia National Laboratories, we collected photonic doppler velocimetry (PDV) data at 8 radii and each of 3 azimuths within 55 mm. Using these PDV velocimetry traces together with Bayesian inference, we estimate delivered current vs. radius vs. time, and will discuss radial current losses and azimuthal asymmetries for a short-circuit synchronous Z pulse. This data will be compared with PIC modeling of the experiment.



[1] H. M. Hess, et al, PoP 25 042702 (2018)

[2] T. M. Hutchinson, et al, JAP, 134, 155901 (2023).

*This material is based upon the work supported by the Department of Energy, National Nuclear Security Administration, under Award No. DE-NA0003870.This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344.Sandia National Laboratories is a multiprogram laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration under Contract No. DE-AC04-94AL85000.

–

Presenters

  • Trevor M Hutchinson

    • Lawrence Livermore Natl Lab
    • Lawrence Livermore National Laboratory

Authors

  • Trevor M Hutchinson

    • Lawrence Livermore Natl Lab
    • Lawrence Livermore National Laboratory

  • Kumar S. Raman

    • Lawrence Livermore National Laboratory

  • Gary P Grim

    • Lawrence Livermore National Laboratory

  • Kurt K Tummel

    • Lawrence Livermore National Laboratory

  • Katherine Chandler

    • Sandia National Laboratories

  • David J. Ampleford

    • Sandia National Laboratories

  • Kurt Tomlinson

    • General Atomics

  • Allen A Crabtree

    • Sandia National Laboratories

  • John E Cortes

    • Lawrence Livermore National Laboratory

  • Nathan B Meezan

    • Pacifc Fusion
    • Pacific Fusion
    • Lawrence Livermore National Laboratory

  • Grafton K Robertson

    • Sandia National Laboratories

  • Keith R LeChien

    • Pacific Fusion

  • William A Stygar

    • Lawrence Livermore National Laboratory