Shock Waves in Gas and Plasma in Strong Magnetic Fields
type: CreativeWork
description: Shock waves in magnetized plasma are central to particle acceleration, high-energyradiation, and energy transport in astrophysical systems. However, direct measurements in the MG field regime relevant to white dwarf accretions, cataclysmic variables, and supernova remnants remain under tested. In this dissertation I develop an experimental platform combining a 50 TW ultrafast laser and a 1-MA pulsed-power generator to produce and diagnose laser-driven shocks propagating through gas and plasma in externally applied megagauss magnetic fields, a strong field regime not tested before. Experiments were performed at the Nevada Terawatt Facility(NTF). The platform uses the approximately 30 J, 0.35 ps-0.8 ns, 1056 nm Leopard laser focused onto 1-2.5 mm Cu rod loads positioned inside the Zebra pulsed-power vacuum chamber. A plasma piston produced by laser ablation drives a shock wave into an ambient hydrogen or nitrogen gas. Zebra drives 0.7-1.5 MA of current, generating azimuthal magnetic fields up to ≥ 100 T at millimeter distances from the rod surface. Magnetic fields were directly measured using two-color Faraday rotation with TGG crystal probes. Multi-frame optical diagnostics were developed and integrated into the Zebra chamber. This includes 266 nm interferometry, 532 nm shadowgraphy, schlieren imaging, 4-frame side-on imaging perpendicular to the rod, and vertical imaging parallel to the rod axis. These diagnostics enable time-resolved measurement of shock front position, curvature, density gradients, and velocity anisotropy, with temporal resolution on the order of several nanoseconds and μm spatial resolution. Detailed gas-jet density profiles between 1018 and 1019 cm-3 were calculated using Abel inversion algorithms. In shots without applied magnetic field, the shock expands quasi-spherically with measured front velocities in the range 500-1600 km/s. In the presence of MG magnetic fields, however, the dynamics change qualitatively. The shock front becomes anisotro…
abstract: Shock waves in magnetized plasma are central to particle acceleration, high-energyradiation, and energy transport in astrophysical systems. However, direct measurements in the MG field regime relevant to white dwarf accretions, cataclysmic variables, and supernova remnants remain under tested. In this dissertation I develop an experimental platform combining a 50 TW ultrafast laser and a 1-MA pulsed-power generator to produce and diagnose laser-driven shocks propagating through gas and plasma in externally applied megagauss magnetic fields, a strong field regime not tested before. Experiments were performed at the Nevada Terawatt Facility(NTF). The platform uses the approximately 30 J, 0.35 ps-0.8 ns, 1056 nm Leopard laser focused onto 1-2.5 mm Cu rod loads positioned inside the Zebra pulsed-power vacuum chamber. A plasma piston produced by laser ablation drives a shock wave into an ambient hydrogen or nitrogen gas. Zebra drives 0.7-1.5 MA of current, generating azimuthal magnetic fields up to ≥ 100 T at millimeter distances from the rod surface. Magnetic fields were directly measured using two-color Faraday rotation with TGG crystal probes. Multi-frame optical diagnostics were developed and integrated into the Zebra chamber. This includes 266 nm interferometry, 532 nm shadowgraphy, schlieren imaging, 4-frame side-on imaging perpendicular to the rod, and vertical imaging parallel to the rod axis. These diagnostics enable time-resolved measurement of shock front position, curvature, density gradients, and velocity anisotropy, with temporal resolution on the order of several nanoseconds and μm spatial resolution. Detailed gas-jet density profiles between 1018 and 1019 cm-3 were calculated using Abel inversion algorithms. In shots without applied magnetic field, the shock expands quasi-spherically with measured front velocities in the range 500-1600 km/s. In the presence of MG magnetic fields, however, the dynamics change qualitatively. The shock front becomes anisotro…
author: Minaker, Zachary
language: en_US
language: English
keywords: Shock Waves, Strong Magnetic Fields
date published: 2025
date modified: 2026-07-27T21:46:30Z
provider: University of Nevada - Reno
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Nevada - Reno