Search NASA⌕ Search
Home/Archive/DOE OSTI

DOE OSTI · 2538434

Enhanced Isomer Population via Direct Irradiation of Solid-Density Targets Using a Compact Laser-Plasma Accelerator

Jacob, Robert E. [University of California, Berkeley, CA (United States); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)] (ORCID:0000000164849917)·Tannous, Speero M. [University of California, Berkeley, CA (United States)] (ORCID:0000000161554021)·Bernstein, Lee A. [University of California, Berkeley, CA (United States); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)]·Brown, Joshua [University of California, Berkeley, CA (United States)]·Ostermayr, Tobias [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)] (ORCID:0000000169131066)·Chen, Qiang [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)]·Schneider, Dieter H. G. [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)]·Schroeder, Carl B. [University of California, Berkeley; Lawrence Berkeley National Laboratory]·van Tilborg, Jeroen [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)]·Esarey, Eric H. [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)]·Geddes, Cameron G. R. [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)]
View original source ↗Read source document ↗Export metadata ↓

Abstract

Excitation of long-lived states in bromine nuclei using a tabletop laser-plasma accelerator providing pulsed (<100 fs) electron beams provided a sensitive probe of γ strength and level densities in the nuclear quasicontinuum and may indicate angular momentum coupling through electron-nuclear interactions. Solid-density active $LaBr_{3}$ targets absorb real and virtual photons up to 35 ± 2.5 MeV and deexcite through γ cascade into different states. Here, a factor of 4.354 ± 0.932 enhancement of the $^{80}Br^{m}/^{80}Br^{g}$ isomeric ratio was observed following electron irradiation, as compared to bremsstrahlung. Additional angular momentum transfer could possibly occur through nuclear-plasma or electron-nuclear interactions enabled by the ultrashort electron beam. Further investigation of these mechanisms could have far-reaching impact including decreased storage of long-term nuclear waste and an improved understanding of heavy element formation in astrophysical settings.

Explore related subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Jacob, Robert E. [University of California, Berkeley, CA (United States); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)] (ORCID:0000000164849917), Tannous, Speero M. [University of California, Berkeley, CA (United States)] (ORCID:0000000161554021), Bernstein, Lee A. [University of California, Berkeley, CA (United States); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)], Brown, Joshua [University of California, Berkeley, CA (United States)], Ostermayr, Tobias [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)] (ORCID:0000000169131066), Chen, Qiang [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)], Schneider, Dieter H. G. [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)], Schroeder, Carl B. [University of California, Berkeley; Lawrence Berkeley National Laboratory], van Tilborg, Jeroen [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)], Esarey, Eric H. [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)], Geddes, Cameron G. R. [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)]. 2025-02-07. Enhanced Isomer Population via Direct Irradiation of Solid-Density Targets Using a Compact Laser-Plasma Accelerator. https://doi.org/10.1103/physrevlett.134.052504

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

KEEP EXPLORING

Related reports

DOE OSTI2026

Design-informed neutronics assessment of long-lived fission product transmutation in a tokamak fusion reactor blanket

This study presents a neutronics-based assessment of the feasibility and viability of transmuting six major long-lived fission products (LLFPs) from light-water reactors, namely 99 Tc, 129 I, 79 Se, 93 Zr, 126 Sn, and 135 Cs, within the blanket region of a tokamak fusion reactor, using the MIT ARC design as a concrete fusion configuration. Monte Carlo neutronics simulations were performed to evaluate LLFP transmutation and to compare the results with a reference boiling water reactor (BWR). The results indicate that transmutation of all six LLFPs is neutronics-feasible in fusion reactors, with transmutation half-lives significantly shorter than their natural decay half-lives. For elemental targets, transmutation of 135 Cs, 126 Sn, and 93 Zr was found potentially viable, as the net mass transmuted exceeded that achievable in the reference BWR under identical target volume and irradiation time. When isotopically separated targets were considered, transmutation of 126 Sn and 93 Zr appeared potentially viable. A parametric study demonstrated that plasma geometry modifications can enhance local neutron flux, increasing the transmuted 93 Zr mass by approximately 33% and reducing the transmutation half-life from approximately 240 years to 180 years. Repositioning the target and adjusting material layer thickness reduced the transmutation half-life of 93 Zr to 67 years and increased the net mass transmuted by a factor of 50. Furthermore, these results demonstrate that fusion reactors can enable LLFP transmutation beyond the practical limits of thermal fission reactors and highlight the critical role of reactor and blanket design optimization. Engineering and fuel-cycle considerations required for deployment are beyond the scope of this neutronics-focused study.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2026

A hybrid Monte Carlo-deterministic second moment method with efficient variance reduction

In this work, we present a hybrid method that combines Monte Carlo with deterministic finite element methods to solve a linear Boltzmann transport equation. Our hybrid method runs orders of magnitude faster than Monte Carlo, without sacrificing accuracy, for a proxy problem from radiative transfer that contains both optically-thick and optically-thin material. We believe that this is the first demonstration of a hybrid Second Moment Method in more than one spatial dimension, the first to consider more than one material, and the first to use variance reduction. Our variance reduction approach arises from an asymptotic analysis in which we show that the magnitude of the scattering source grows without bound. We transform the problem to compute the deviation of the radiation intensity from isotropy. The magnitude of the source in the transformed problem is bounded, and the quality of the hybrid method solution is dramatically improved by a substantial reduction in the variance.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗