Abstract Details
Abstracts
Author: Genia V. Vogman
Requested Type: Poster
Submitted: 2025-03-05 16:45:43
Co-authors: J. H. Hammer, A. Ho
Contact Info:
Lawrence Livermore National Laboratory
7000 East Ave
Livermore, CA 94550
USA
Abstract Text:
Pulsed power inertial confinement fusion experiments deliver up to 26 MA of current to a Z-pinch load using in-vacuum magnetically-insulated transmission lines, which are designed to prevent high-voltage arcs. Performance of these experiments is limited by anomalous transport caused by collisionless, microturbulent, low-beta plasmas that are produced at electrode surfaces of these transmission lines. Acceleration-driven lower hybrid drift instabilities (LHDIs) have been identified as leading candidate drivers of anomalous resistivity and heating in these systems, leading to difficult-to-characterize plasma conditions. We show that in the case where current is perpendicular to the background magnetic field, it is possible to derive a complete quasilinear model description for LHDI transport, such that the coupled velocity-space diffusion equations for each species have self-consistent time-evolving diffusion coefficients. The model applies to arbitrary distribution functions that can be expressed in terms of one velocity coordinate. Furthermore, the model conserves energy, accounts for resonant and non-resonant particle-wave interactions, and makes no assumption on the saturated state conditions. The model is solved numerically and validated using fully nonlinear high-order accurate continuum kinetic Vlasov-Poisson simulations, which show that the model is predictive of anomalous transport to a factor of order unity. While unperturbed-orbit susceptibilities and lack of damping limit the model's ability to predict nonlinear physics, we show that the model yields powerful insights that, together with GPU-accelerated continuum kinetic simulations, help overcome these limitations. Prepared by LLNL under Contract DE-AC52-07NA27344. LLNL-ABS-2003081
Characterization: 1.0
Comments: