Laboratory Demonstration of Collisionless Blob Formation via Laser-Produced Plasma Self-Focusing
Strongly localized, propagating plasma density structures that are capable of crossing magnetic field lines are known as "blobs." Here we demonstrate a novel mechanism for the formation and propagation of an ion gyroradius-scale blob-cavity structure at the interface between a super-Alfvénic laser-produced plasma (LPP) and an ambient magnetized plasma. The LPP self-focuses along the edge of the diamagnetic cavity which results in a dense, jetlike structure as compared to ballistic motion. This collimated flow couples momentum to the ambient plasma through a collisionless process known as Larmor coupling. The Larmor electric fields locally displace the ambient ions forming a blob above the LPP flow. In the region between a gyrating blob and collimated LPP flow, a secondary cavity of expelled magnetic field forms. These findings are supported by particle-in-cell simulations that replicate the blob formation mechanism and provide insight to similar processes in space, astrophysical, and laboratory settings characterized by ion kinetic scales.
Authors
- Shreekrishna Tripathi (ORCID: https://orcid.org/0000-0002-6500-2272)
- S. Vincena (ORCID: https://orcid.org/0000-0002-6468-5710)
- Misa Cowee (ORCID: https://orcid.org/0000-0003-3117-4030)
- A. Lê (ORCID: https://orcid.org/0000-0002-9381-6839)
- J. J. Pilgram (ORCID: https://orcid.org/0000-0003-3488-1881)
- Carmen Constantin (ORCID: https://orcid.org/0000-0002-8439-5518)
- R. S. Dorst (ORCID: https://orcid.org/0000-0002-0356-1036)
- David J. Larson (ORCID: https://orcid.org/0000-0003-0814-8555)
- Derek B. Schaeffer (ORCID: https://orcid.org/0000-0003-1675-5910)
- D. Winske (ORCID: https://orcid.org/0000-0003-1600-4084)
- C. Niemann (ORCID: https://orcid.org/0000-0001-5489-9144)
Institutions
- Lawrence Livermore National Laboratory (US)
- Los Alamos National Laboratory (US)
- University of California, Los Angeles (US)
Publication Details
- Journal
- Physical Review Letters
- Published
- 2025-02-06
- DOI
- https://doi.org/10.1103/physrevlett.134.055101
- Primary Topic
- Laser-induced spectroscopy and plasma
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- National Science Foundation
- U.S. Department of Energy
- Defense Threat Reduction Agency
- Laboratory Directed Research and Development
- Lawrence Livermore National Laboratory
- Los Alamos National Laboratory