Characterization of fast magnetosonic waves driven by interaction between magnetic fields and compact toroids

Magnetosonic waves are low-frequency, linearly polarized magnetohydrodynamic (MHD) waves that can be excited in any electrically conducting fluid permeated by a magnetic field. They are commonly found in space, responsible for many well-known features, such as heating of the solar corona and acceleration of energetic electrons in Earth's inner magnetosphere. In this work, we present observations of magnetosonic waves driven by injecting compact toroid (CT) plasmas into a static Helmholtz magnetic field at the Big Red Ball (BRB) Facility at Wisconsin Plasma Physics Laboratory (WiPPL). We first identify the wave modes by comparing the experimental results with the MHD theory, and then study how factors such as the background magnetic field affect the wave properties. Since this experiment is part of an ongoing effort of forming a target plasma with tangled magnetic fields as a novel fusion fuel for magneto-inertial fusion (MIF, aka magnetized target fusion), we also discuss a future possible path of forming the target plasma based on our current results

Inferring the temperature profile of the radiative shock in the COAX experiment with shock radiography, Dante, and spectral temperature diagnostics

Predicting and modeling the behavior of experiments with radiation waves propagating through low-density foams require a detailed quantification of the numerous uncertainties present. In regimes where a prominent radiative shock is produced, key dynamical features include the shock position, temperature, and curvature and the spatial distribution and temperature of the corresponding supersonic radiation wave. The COAX experimental platform is designed to constrain numerical models of such a radiative shock propagating through a low-density foam by employing radiography for spatial and shock information, Dante for characterizing the x-ray flux from the indirectly driven target, and a novel spectral diagnostic designed to probe the temperature profile of the wave. In this work, we model COAX with parameterized 2D simulations and a Hohlraum-laser modeling package to study uncertainties in diagnosing the experiment. The inferred temperature profile of the COAX radiation transport experiments has been shown to differ from simulations more than expected from drive uncertainties that have been constrained by simultaneous soft x-ray flux and radiography measurements. © 2022 Author(s).Open access articleThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]