Engineering Papers⌕ Search
Home/Archive/DOE OSTI

DOE OSTI · 3625666

Structure of Self-Generated Magnetic Fields in Laser-Solid Interaction from Proton Tomography

Griff-McMahon, J. [Princeton University, NJ (United States); Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)] (ORCID:0000000207740613)·Walsh, C. A. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)] (ORCID:0000000349945024)·Valenzuela-Villaseca, V. [Princeton University, NJ (United States); Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Massachusetts Institute of Technology, Cambridge, MA (United States)] (ORCID:0000000167721441)·Malko, S. [Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)] (ORCID:0000000310411092)·McCluskey, B. [Princeton University, NJ (United States); Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)] (ORCID:0009000618670020)·Lezhnin, K. [Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)] (ORCID:000000027636069X)·Landsberger, H. [Princeton University, NJ (United States); Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)] (ORCID:0000000278001391)·Hopkins, L. Berzak [Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)] (ORCID:0000000291875667)·Fiksel, G. [University of Michigan, Ann Arbor, MI (United States)] (ORCID:0000000194860885)·Rosenberg, M. J. [University of Rochester, NY (United States)] (ORCID:000000029924304X)·Schaeffer, D. B. [University of California Los Angeles, CA (United States)] (ORCID:0000000316755910)·Fox, W. [Princeton University, NJ (United States); Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States); University of Maryland, College Park, MD (United States)] (ORCID:000000016289858X)
View original source ↗Read source document ↗Export metadata ↓

Abstract

Self-generated magnetic fields in laser-solid interactions are experimentally characterized to reveal the 3D location and local field strength, rather than path-integrated quantities, using multi-view proton radiography and tomographic inversion. We infer magnetic fields that extend several millimeters off the target into the hot, rarefied corona, sufficient to strongly magnetize the plasma (Ω e τ e ≫ 1). The data are compared to MHD simulations incorporating recent improvements in modeling magnetic field generation and transport; the volume-averaged coronal field strength and magnetic flux agree to within 25% using a model with magnetic re-localization of transport, although the near-target morphology is not reproduced. This work demonstrates tomographic proton radiography as a valuable tool for investigating magnetic fields in laser-produced plasmas.

Explore related subjects

High-energy-density plasmasLaser-induced magnetic fields in plasmas

Keep this discovery

BibTeXRIS

Griff-McMahon, J. [Princeton University, NJ (United States); Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)] (ORCID:0000000207740613), Walsh, C. A. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)] (ORCID:0000000349945024), Valenzuela-Villaseca, V. [Princeton University, NJ (United States); Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Massachusetts Institute of Technology, Cambridge, MA (United States)] (ORCID:0000000167721441), Malko, S. [Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)] (ORCID:0000000310411092), McCluskey, B. [Princeton University, NJ (United States); Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)] (ORCID:0009000618670020), Lezhnin, K. [Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)] (ORCID:000000027636069X), Landsberger, H. [Princeton University, NJ (United States); Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)] (ORCID:0000000278001391), Hopkins, L. Berzak [Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)] (ORCID:0000000291875667), Fiksel, G. [University of Michigan, Ann Arbor, MI (United States)] (ORCID:0000000194860885), Rosenberg, M. J. [University of Rochester, NY (United States)] (ORCID:000000029924304X), Schaeffer, D. B. [University of California Los Angeles, CA (United States)] (ORCID:0000000316755910), Fox, W. [Princeton University, NJ (United States); Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States); University of Maryland, College Park, MD (United States)] (ORCID:000000016289858X). 2026-08-10. Structure of Self-Generated Magnetic Fields in Laser-Solid Interaction from Proton Tomography. https://doi.org/10.1103/vh46-3rsh

Cite the original work for its findings. Save a collection to share your selection of sources.

Discover connections

Laser-induced magnetic fields in plasmas subject

Connections use source metadata and explicit phrase matches, not verified experimental comparisons.

KEEP EXPLORING

Related reports

NASA NTRS2026

Recommended Practices in Laser-Induced Fluorescence (LIF) Diagnostics for Electric Propulsion

Laser-induced fluorescence (LIF) spectroscopy uses Doppler-shifted laser photons to excite a bound electron transition in an atom or ion, with subsequent fluorescence emission detected in order to measure the local velocity distribution function (VDF) and/or particle density. Due to its non-invasive nature, high spatial resolution, and acceptable difficulty of implementation, LIF has become a favored diagnostic for electric propulsion (EP) plasmas, particularly in the study of Hall thrusters. This paper presents recommended best practices for LIF measurements in electric thrusters, drawn from over three decades of implementation heritage in the EP community. Focusing on both single-photon LIF (typically used to measure VDFs) and two-photon LIF (TALIF, typically used to determine densities), the paper covers selection of atomic transitions to target, experimental setups, and interpretation of data. A number of special topics and advanced applications are discussed, including uncertainty analysis, techniques for high-speed measurements, and applications to a variety of propellants.

plasma plume↗
DOE OSTI2025

Challenges in Continuous In-Field Critical Current Testing of High-Temperature Superconducting Tapes: Thermal and Mechanical Perspectives

High-temperature superconductors (HTS) are essential for ultra-high-field applications requiring exceptional current-carrying capacity under extreme conditions. However, systematic characterization of critical current in long-length conductors remains challenging due to complex thermal, electromag netic, and mechanical interactions during continuous testing. This study reports the development of a continuous in-field magnetization testing system for position-dependent critical current measurement in HTS tapes at 20 K under 7.5 T fields applied normal to the tape plane, enabling identification of performance-limiting regions that could compromise magnet stability. Here, the system addresses two fundamental challenges inherent to cryogenic reel to-reel testing. First, thermal management requires continuous cooling of a moving conductor to 20 K, achieved through liquid nitrogen precooling combined with a 100 W@20 K Gifford McMahon cryocooler. Second, screening currents in high fields generate Lorentz forces that induce twisting, bowing, and potential delamination. To mitigate these risks, we propose mechanical reinforcement and active current density suppression strategies. Numerical simulations using the stream function formulation reveal four primary failure modes: frictional heating at guide interfaces, unstable equilibria causing deformation, transverse current-induced stresses at guide transitions, and unsupported forces in vertical spans. Our mitigation strategies include PTFE coated guides to minimize friction, spring-loaded stabilization mechanisms to maintain tape alignment, controlled pre-heating using the liquid nitrogen thermal jacket to suppress critical current at stress points, and optimized guide positioning to minimize force accumulation. The experimental system is nearing completion, with testing planned to commence within two months. Preliminary validation at 65 K under 0.5 T demonstrates strong correlation between simulation-predicted mechanical instabilities and observed critical current variations during conductor tran sitions through the measurement region. These findings establish a robust foundation for quality assurance protocols essential to next-generation superconducting magnet applications.

Chen, Siwei [Princeton Plasma Physics Laboratory (↗
DOE OSTI2026

Plasma flow generation and particle acceleration from expanding magnetic bubbles

Impulsive plasma dynamics in the laboratory are often driven by rising electric currents, yet their quantitative plasma response has not been well established. By means of fully kinetic particle-in-cell simulations and laser-driven capacitor-coil experiments, we show that a rising current expels plasma, forming an expanding magnetic bubble and accelerating particles. The expansion front velocity scales with the Alfvén speed determined by the magnetic field at its inner edge and the plasma density at its outer edge. This mechanism establishes impulsive current drive as a fundamental way that generates plasma flows and accelerates particles in laboratory plasmas, with potential relevance to astrophysics.

Zhang, Yang [Princeton University, NJ (United Stat↗