Simple and Robust Algorithm for Unfolding Hard X-ray Spectra from Filter Stack Spectrometers

POSTER

Abstract

The Filter Stack Spectrometer (FSS) is an instrument that measures x-ray spectra using alternating filters and image plates (IPs). The FSS has several attractive features: it is an easy-to-field, portable, and passive diagnostic capable of measuring hard (10s of keV to 10s of MeV) x-ray spectra for radiographic systems and HED physics experiments. However, unfolding x-ray spectra from the IP signals is an ill-posed problem requiring physics principles to constrain the unfold. Strong constraints can enforce a unique solution but can also strongly impose preconceptions onto the inferred x-ray spectrum.

Perturbative minimization (PM) has been shown to be an effective method for unfolding x-ray transmission data (without scatter), with the restriction that filter attenuation coefficients monotonously decrease with x-ray energy [1,2]. Here, we extend the PM method to unfold x-ray spectra from FSS data (which includes scatter) without the previous restriction and without a physics-informed initial guess. We apply the algorithm to unfold a set of synthetic spectra with known ground truths, as well as experimental spectra obtained at OMEGA EP and the Texas Petawatt Laser Facility.

References:

[1] Waggener et al., Med. Phys. 26, 1269-1279 (1999).

[2] Iwasaki et al., Rad. Phys. Chem. 67, 81-91 (2003).

*This work was supported by the U.S. Department of Energy through the Los Alamos National Laboratory. Research presented in this presentation was supported in part by the Laboratory Directed Research and Development program of Los Alamos National Laboratory under project number 20220018DR. Los Alamos National Laboratory is operated by Triad National Security, LLC, for the National Nuclear Security Administration of U.S. Department of Energy (Contract No. 89233218CNA000001).

Presenters

  • Chun-Shang Wong

    • Los Alamos National Laboratory

Authors

  • Chun-Shang Wong

    • Los Alamos National Laboratory

  • Joseph Strehlow

    • Los Alamos National Laboratory, Los Alamos, NM 87544, USA
    • Los Alamos National Laboratory

  • David P Broughton

    • Los Alamos National Laboratory

  • Scott V Luedtke

    • Los Alamos National Laboratory

  • Chengkun Huang

    • Los Alamos Natl Lab
    • Los Alamos National Laboratory, Los Alamos, NM 87544, USA

  • Mariana Alvarado Alvarez

    • Los Alamos National Laboratory

  • Robert E Reinovsky

    • Los Alamos Natl Lab

  • Thomas R Schmidt

    • Los Alamos National Laboratory
    • Los Alamos National Labs

  • Jeph Wang

    • LANL
    • Los Alamos National Laboratory

  • Bradley T Wolfe

    • Los Alamos National Laboratory

  • Sasi Palaniyappan

    • Los Alamos Natl Lab
    • Los Alamos National Laboratory
    • Los Alamos National Laboratory, Los Alamos, NM 87544, USA
    • Los Alamos National Lab

  • Steven H Batha

    • Los Alamos Natl Lab

  • Brian J Albright

    • Los Alamos Natl Lab
    • Los Alamos National Laboratory, Los Alamos, NM 87544, USA