Gas Transport in the Insensitive High Explosive PBX 9502
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Small-scale laboratory experiments were performed to analyze gas transport mechanics in PBX 9502, an insensitive high explosive (IHE) composition. Two independent investigations are reported here. First, gas permeametry and dynamic pycnometry techniques were used to measure the molecular flow (Knudsen) coefficient and the internally interconnected void fraction of pristine and thermally damaged samples in two uniaxial pressing orientations. The permeability of PBX 9502 was found to be unmeasurably low (of the same order of magnitude as PTFE) with gas transport being diffusion-dominated. Secondly, a pressure vessel experiment was developed to measure quasi-static and dynamic gas generation as the explosive was heated to self-ignition (cookoff). The gas generation results and the permeability/diffusivity findings provide evidence that PBX 9502 remains impermeable until seconds prior to self-ignition. At ignition, internal void-pressure drives macro-scale cracking and the sample becomes uniformly incorporated in the following deconsolidating deflagration. These results are discussed within the context of previous observations of pressure-dependent cookoff behavior of PBX 9502 and provide a more complete description of thermal damage evolution in this explosive composition.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE National Nuclear Security Administration (NNSA)
- Grant/Contract Number:
- 89233218CNA000001
- OSTI ID:
- 1635513
- Alternate ID(s):
- OSTI ID: 1606598
- Report Number(s):
- LA-UR-19-29476
- Journal Information:
- Propellants, Explosives, Pyrotechnics, Vol. 45, Issue 6; ISSN 0721-3115
- Publisher:
- WileyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Ignition experiments and models of a plastic bonded explosive (PBX 9502)
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journal | March 2014 |
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