High explosives (PBX9502) characterization using computerized tomography

X-ray computed axial tomography (CAT or CT) is an advanced imaging technique which provides three-dimensional nondestructive inspection and characterization of materials, components and assemblies. The Lawrence Livermore National Laboratory (LLNL) and the Mason Hanger-Silas Mason Co., Pantex Plant are cooperating to examine the use of CT Technology to inspect high-explosive (HE) pressings. The goals of this joint project are to study the HE pressing process using computed tomography scanners, to provide a foundation for the further development of industrial CT scanners, and to work with the private sector on the design and implementation of an automated CT inspection scanner to be used in the manufacturing process of high explosives at the Pantex Plant. The early detection of defective HE pressings will reduce the cost and improve the safety of the high-explosives production cycle. At present, all pressings are bulk density tested. In addition, samples are randomly selected from each pressing lot for destructive core sampling to obtain an estimate of internal density gradients. CT is a viable technology for a high-explosives inspection system. CT measures density variations, detects foreign inclusions and voids with a probability of detection as good as or better than present inspection techniques. In addition, CT canmore » be fully automated to allow for a 100% sample inspection. LLNL has the advantage of several different in-house built CT scanners to bring to bear on the inspection of high explosives. A preliminary study was performed to evaluate the LLNL CT scanners and prove the characterization principles associated with CT on small PBX9502 high-explosive samples. This paper summarizes the results obtained, and introduces the capabilities of LLNL's Nondestructive Evaluation Section CT scanners. 36 refs., 50 figs.« less