Proton Imaging of Diamagnetic Cavity Formation in Expanding Laser-Driven Plasma at the OMEGA Laser Facility

POSTER

Abstract



In this work, we present experiments conducted at the OMEGA laser facility to investigate the collimation of magnetized plasma outflows resulting from a diamagnetic cavity. A 1-ns, 4.5-kJ laser pulse was used to irradiate one side of CH and zinc planar target, producing an expanding plasma plume from the rear surface. A uniform external magnetic field of 20 T was applied using a pair of Helmholtz coils. Synthetic proton radiography at 20 ns, produced based on FLASH simulations, pending experimental validation, shows a region of reduced magnetic field within the plume relative to the background field, consistent with the formation of a diamagnetic cavity. In the solar context, high-speed plasma jets—considered potential contributors to the solar wind—are observed to propagate along open magnetic field lines in coronal holes. These jets are strongly collimated by magnetic pressure, with typical widths of ~100 km and lengths of several megameters, likely due to the presence of an internal diamagnetic cavity.

*The experiment was conducted at the Omega Laser Facility with the beam time through the National Laser Users’ Facility user program. This material is based upon work supported by the Department of Energy [National Nuclear Security Administration] University of Rochester “National Inertial Confinement Fusion Program” under Award Number(s) DE-NA0004144. Work performed under the auspices of the U.S. Department of Energy by General Atomics under NNSA Contract 89233124CNA000365. This work was supported by the Delaware NASA EPSCoR RID seed grant program, Bartol Research Institute, and the University of Delaware. This research made use of PlasmaPy version 2024.10.0, a community-developed open source Python package for plasma research and education (PlasmaPy Community et al. 2024). The software used in this work was developed in part by the DOE NNSA- and DOE O ce of Sciencesupported Flash Center for Computational Science at the University of Chicago and the University of Rochester.

Presenters

  • Chung Hei Leung

    • University of Delaware

Authors

  • Chung Hei Leung

    • University of Delaware

  • Yigeng Tian

    • University of Delaware

  • Arijit Bose

    • University of Delaware

  • Luke A Ceurvorst

    • University of Rochester

  • Peter V Heuer

    • University of Rochester
    • Laboratory for Laser Energetics (LLE)

  • Dino Mastrosimone

    • LLE

  • Jonathan L Peebles

    • Laboratory for Laser Energetics, University of Rochester
    • University of Rochester