Time-resolved X-ray Thomson Scattering and Fluorescence Spectroscopy for IFE Target Design

ORAL

Abstract

Understanding the behavior of polymer foams at high energy density conditions is crucial to advance inertial fusion energy research [1]. Here, we present data measuring the thermodynamic state of these materials at megabar pressures. At the Matter in Extreme Conditions Endstation of the Linac Coherent Light Source, we heat samples using an optical, high-intensity, femtosecond laser and dynamically probe them with ultra-short, coherent X-ray pulses of high peak brightness. Our data resolve the ultrafast response to laser heating with sub-ps resolution, measuring plasma temperatures exceeding 50 eV [2]. At the OMEGA laser facility, we study spherically converging implosions of foam shells. In both experiments, we field X-ray Thomson scattering measurements in forward and backward scattering geometries to capture both collective and non-collective electron behavior and determine the temperature of the sample. Simultaneously, X-ray fluorescence spectroscopy is used to measure the emission from a mid-Z dopant, providing complementary information on the plasma conditions. By combining these techniques, we obtain temporally resolved temperature measurements of the transient warm dense matter states and lay the foundation for future precision studies of laser-driven polymer foams wetted with liquid nuclear fuels.



References

[1] Fusion Energy Sciences Workshop on Inertial Fusion Energy, “Report of the Fusion Energy Sciences Workshop on Inertial Fusion Energy,” Tech. Rep. (U.S. Department of Energy, Office of Science, Fusion Energy Sciences, 2023).

[2] Martin, W. M., et al. "Characterizing laser-heated polymer foams with simultaneous x-ray fluorescence spectroscopy and Thomson scattering at the Matter in Extreme Conditions Endstation at LCLS." Physics of Plasmas 32.7 (2025).

*W.M.M. acknowledges support from the National Science Foundation Graduate Research Fellowship Program under Grant No. DGE-2146755. This work was funded by the DOE Office of Science, Fusion Energy Science under FWP100182. We acknowledge support from Department of Energy (DOE), Office of Science, Fusion Energy Sciences, under award no. DE-SC 0024882: IFE-STAR was issued as SLAC FWP 101126. The portion of this work carried out at LLNL was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344. The work of M.J.M, T.D., M.B., and J.N. was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344, and the work of M.J.M was supported by Laboratory Directed Research and Development (LDRD) Grant No. 22-ERD-005. X. X. and M. M. acknowledge support by Lawrence Livermore National Laboratory's Lab Directed Research and Development Program (23-ERD-027). RWF acknowledges support from DOE, National Nuclear Security Administration under Award Number DE-NA0004147, and Office of Science, Office of Fusion Energy Sciences, under Federal Prime Agreement DE-AC02-05CH11231. The work of H.B. and T.G. was partially supported by the Center for Advanced Systems Understanding (CASUS) which is financed by Germany's Federal Ministry of Education and Research (BMBF) and by the Saxon state government out of the State budget approved by the S

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Publication: Martin, W. M., et al. "Characterizing laser-heated polymer foams with simultaneous x-ray fluorescence spectroscopy and Thomson scattering at the Matter in Extreme Conditions Endstation at LCLS." Physics of Plasmas 32.7 (2025).

Presenters

  • Willow Moon Martin

    • Stanford University

Authors

  • Willow Moon Martin

    • Stanford University