{"paper":{"title":"First-principles simulation of shocked H-He mixture along the principal Hugoniot","license":"http://creativecommons.org/licenses/by/4.0/","headline":"Ab initio simulations of shocked H-He mixtures match experimental reflectivity but show no discontinuities indicative of demixing.","cross_cats":[],"primary_cat":"cond-mat.other","authors_text":"Ammar A. Ellaboudy, S. X. Hu, Valentin V. Karasiev","submitted_at":"2026-05-02T19:34:42Z","abstract_excerpt":"Recent laser-shock experiments on an H--He mixture containing 11~$\\%$ helium (atomic fraction) have suggested the presence of an immiscibility region inside Jupiter. Reflectivity measurements were used as the primary diagnostic of H--He demixing, with discontinuities in the optical reflectivity proposed as a signature of phase separation under conditions relevant to Jupiter's interior. Here, we investigate shock-compressed H--He using \\textit{ab initio} molecular dynamics simulations with optical properties evaluated within the Kubo--Greenwood formalism. The equation of state and ionic configu"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"These results suggest that reflectivity alone may not provide a unique or sensitive diagnostic of H-He demixing at low helium concentrations under these conditions.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"That the RS-KDT0 range-separated thermal hybrid functional and the Tr2SCANL meta-GGA accurately capture both the equation of state and the optical response without systematic bias in the warm-dense-matter regime relevant to the experiments.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"Ab initio molecular dynamics simulations of shocked H-He mixtures reproduce experimental reflectivity values without discontinuities at conditions where demixing was previously inferred from data.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"Ab initio simulations of shocked H-He mixtures match experimental reflectivity but show no discontinuities indicative of demixing.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"a7f312570b704caa0e3ea1bb675d76b20d5d4ee6809868035b64dbbbfaa28938"},"source":{"id":"2605.01593","kind":"arxiv","version":1},"verdict":{"id":"e7162f2a-d08b-4280-80cc-6346fe5d9a3c","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-10T14:55:17.439343Z","strongest_claim":"These results suggest that reflectivity alone may not provide a unique or sensitive diagnostic of H-He demixing at low helium concentrations under these conditions.","one_line_summary":"Ab initio molecular dynamics simulations of shocked H-He mixtures reproduce experimental reflectivity values without discontinuities at conditions where demixing was previously inferred from data.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"That the RS-KDT0 range-separated thermal hybrid functional and the Tr2SCANL meta-GGA accurately capture both the equation of state and the optical response without systematic bias in the warm-dense-matter regime relevant to the experiments.","pith_extraction_headline":"Ab initio simulations of shocked H-He mixtures match experimental reflectivity but show no discontinuities indicative of demixing."},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2605.01593/integrity.json","findings":[],"available":true,"detectors_run":[{"name":"ai_meta_artifact","ran_at":"2026-05-20T17:39:20.689183Z","status":"completed","version":"1.0.0","findings_count":0},{"name":"doi_compliance","ran_at":"2026-05-19T17:09:10.877089Z","status":"completed","version":"1.0.0","findings_count":0}],"snapshot_sha256":"6dce10b5f016e5095eba618ed12d180e68c68a6a56669142ca58429367d3fc3b"},"references":{"count":48,"sample":[{"doi":"","year":2017,"title":"S. M. Wahl, W. B. Hubbard, B. Militzer, T. Guillot, Y. Miguel, N. Movshovitz, Y. Kaspi, R. Helled, D. Reese, E. Galanti, S. Levin, J. E. Connerney, and S. J. Bolton, Comparingjupiterinteriorstructurem","work_id":"654feb73-5333-482b-996a-0e104ed22cdf","ref_index":1,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2019,"title":"F. Debras and G. Chabrier, New models of jupiter in the context of juno and galileo, The Astrophysical Journal 872, 100 (2019)","work_id":"a396cadd-7719-4330-97d7-5afd0c779e12","ref_index":2,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2020,"title":"C. R. Mankovich and J. J. Fortney, Evidence for a di- chotomy in the interior structures of jupiter and saturn from helium phase separation, The Astrophysical Journal 889, 51 (2020)","work_id":"fdeaae31-a4c1-4189-85d9-88151d1d8994","ref_index":3,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2024,"title":"S. Howard, S. Müller, and R. Helled, Evolution of jupiter and saturn with helium rain, Astronomy & Astrophysics 689, A15 (2024)","work_id":"186f4ff2-a18e-420e-ab96-66ec7021f3a9","ref_index":4,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2025,"title":"A. Sur, R. Tejada Arevalo, Y. Su, and A. Burrows, Si- multaneous evolutionary fits for jupiter and saturn incor- porating fuzzy cores, The Astrophysical Journal Letters 980, L5 (2025)","work_id":"781fb122-ca34-4e35-850a-d844806209c0","ref_index":5,"cited_arxiv_id":"","is_internal_anchor":false}],"resolved_work":48,"snapshot_sha256":"3c63476ec57999d72ed91d29c30d2fc947cf8e01a5fb0a2cbed0f3df6e7475c7","internal_anchors":1},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}