Decomposition-Guided Diffusion Language Models for Inertial Confinement Fusion Prediction

Xiang Zhang, Varchas Gopalaswamy, Rahman Ejaz, Riccardo Betti, Dongfang Liu


Abstract
Inertial confinement fusion (ICF) is a leading pathway toward clean energy, but each shot at the National Ignition Facility costs on the order of one million dollars, making accurate AI surrogates a high-value target. We study exogenous-driven ICF waveform prediction, where a 512-step neutron-rate diagnostic must be inferred directly from a laser pulse and target design parameters, with no historical response observed. The regime stresses standard time-series predictors with temporal sparsity (picosecond peak in a nanosecond window), input-output scale mismatch (under 300 real shots), and peak sensitivity (picosecond timing). We propose ICF-DLM, to our knowledge the first LM-based ICF predictor, combining (i) a physics-typed decomposition into yield YDT, peak timing tpeak, and local waveform wlocal; (ii) bidirectional denoising that defers commitment to peak location; and (iii) a physics-driven PPO reward re-injecting metric structure across numeric tokens. On ICFBench (50K simulations + 232 experimental shots), ICF-DLM cuts peak-timing error from 11.6 to 9.2 steps over a matched autoregressive LLaMA-3-8B and outperforms classical sequence models and LLM-based time-series predictors. Beyond ICF, the recipe shows potential to address science domains with low data and sparse events.
Anthology ID:
2026.findings-emnlp.646
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
13567–13582
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.646/
DOI:
10.18653/2026.findings-emnlp.646
Bibkey:
Cite (ACL):
Xiang Zhang, Varchas Gopalaswamy, Rahman Ejaz, Riccardo Betti, and Dongfang Liu. 2026. Decomposition-Guided Diffusion Language Models for Inertial Confinement Fusion Prediction. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 13567–13582, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Decomposition-Guided Diffusion Language Models for Inertial Confinement Fusion Prediction (Zhang et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.646.pdf