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Extracting the underlying energy spectrum from these detectors requires solving an ill-posed inverse problem, often complicated by noise, secondary particle contamination, and uncertainties in the detector response. In this work, we introduce an open-source unfolding framework (ggfauvel\/CMA-unfold) [ggfauvel\/CMA-unfold: Initial Public Release (2025)] based on the covariance matrix adaptation evolution strategy, designed to reconstruct photon spectra directly from depth-dose profiles without imposing restrictive parametric assumptions. The algorithm demonstrates high robustness, accurately recovering complex spectral shapes while tolerating percent-level deviations in individual detector layers. This approach provides a flexible and noise-resilient tool for the analysis of stacking calorimeter data, with particular relevance for bremsstrahlung diagnostics in high-intensity laser and inertial confinement fusion applications.<\/jats:p>","DOI":"10.1063\/5.0322562","type":"journal-article","created":{"date-parts":[[2026,7,28]],"date-time":"2026-07-28T13:03:03Z","timestamp":1785243783000},"update-policy":"https:\/\/doi.org\/10.1063\/aip-crossmark-policy-page","source":"Crossref","is-referenced-by-count":0,"title":["CMA-unfold: A covariance matrix adaptation unfolding algorithm for stacked calorimeter detectors"],"prefix":"10.1063","volume":"97","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-1088-3412","authenticated-orcid":false,"given":"G.","family":"Fauvel","sequence":"first","affiliation":[{"name":"University of Bordeaux, CELIA, CNRS, CEA 1 , UMR 5107, F-33405 Talence,","place":["France"]},{"name":"ELI Beamlines Facility|The Extreme Light Infrastructure ERIC Za Radnic\u00ed 835 2 , 25241 Doln\u00ed B\u0159e\u017eany,","place":["Czech Republic"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0597-0976","authenticated-orcid":false,"given":"A.","family":"Arefiev","sequence":"additional","affiliation":[{"name":"3 Center for Energy Research, University of California San Diego, La Jolla, California 92093, USA"},{"name":"4 Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, California 92093, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5834-1161","authenticated-orcid":false,"given":"M. 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