Experiments at New X-Ray Facility May Lead to Better Explosive Modeling

Evolution of Carbon Clusters in the Detonation Products of the Triaminotrinitrobenzene (TATB)-Based Explosive PBX 9502.

The detonation of carbon-rich high explosives yields solid carbon as a major constituent of the product mixture, and depending on the thermodynamic conditions behind the shock front, a variety of carbon allotropes and morphologies may form and evolve.

November 20, 2017 | Source: Los Alamos National Laboratory, lanl.gov, 6 Nov 2017, Kevin Roark

For the first time in the U.S., time-resolved small-angle x-ray scattering (TRSAXS) is used to observe ultra-fast carbon clustering and graphite and nanodiamond production in the insensitive explosive Plastic Bonded Explosive (PBX) 9502, potentially leading to better computer models of explosive performance.

“Carbon clusters are produced during the chemical process of detonation in high explosives,” said Dana Dattelbaum, of Explosive Science and Shock Physics Division. “The carbon particle size, shape, composition and their evolution in time helps us understand how explosives deliver energy over a given time frame.”

The research was published in the online version of the Journal of Physical Chemistry (C) in August. Using TRSAXS at the newly-commissioned Dynamic Compression Sector of the Advanced Photon Source at Argonne National Laboratory, researchers from Los Alamos and Lawrence Livermore national laboratories detonated small samples of TATB-based (triamino trinitrobenzene) PBX 9502 while high-brilliance x-rays are scattered by the solid carbon products formed in the detonation. Collaborators also included scientists and technicians from Argonne and Washington State University.

Researchers found that the creation of carbon clusters happens much faster than previously thought, and the composition of the carbon is very different than had been assumed.

The products of detonation, the particle size dynamics and type of carbon produced can correlate directly to the type of explosive, and improving computer models of explosive performance, leading to better predictive capability in assuring the safety, security, and effectiveness of the U.S. nuclear deterrent.