Deciphering decomposition pathways of high explosives with cryogenic X-ray Raman spectroscopy

• 成果类型: Article
• 署名作者: Mellone, Oscar A. Paredes; Nielsen, Michael H.; Babicz Jr, Jeffrey Thomas; Vinson, John; Willey, Trevor M.; Sokaras, Dimosthenis
• 署名单位: Stanford University; United States Department of Energy (DOE); SLAC National Accelerator Laboratory; United States Department of Energy (DOE); Lawrence Livermore National Laboratory; National Institute of Standards & Technology (NIST) - USA
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-11012
• DOI: 10.1073/pnas.2426320122
• 发表日期: 2025-06-10
• 关键词: radiation-induced decomposition; thermal-decomposition; molecular-dynamics; electron-scattering; mechanism; damage; morphology; cl-20

摘要

We employed cryogenic X-ray Raman spectroscopy to investigate the early-stage decomposition of the high explosive molecule hexanitrohexaazaisowurtzitane (CL-20). By systematically varying the radiation dose under cryogenic conditions, we induced the decomposition of the molecule using ionizing radiation and observed the evolution of spectral features at the carbon, nitrogen, and oxygen K edges. Through extensive first-principles calculations, we identified key intermediates in the early stages of the decomposition process, resulting from C-C and C-N bond cleavage which leads to the opening of the internal cage structure. A detailed analysis of spectral trends and fingerprints provided evidence supporting N-NO2 homolytic cleavage as the primary initial decomposition pathway. The combination of advanced core-level spectroscopy methods and state-of-the-art theoretical calculations enabled a comprehensive characterization of the molecular changes induced by controlled radiation dose exposures. Our findings establish a benchmark for understanding the decomposition chemistry of high-explosive materials, offering important insights into their stability and reactivity under extreme conditions.