PROTON RADIOGRAPHY OF EXPLOSIVELY DISPERSED METAL PARTICLES WITH VARYING CARRIER FLUID

A series of experiments performed at Los Alamos National Laboratory aimed to provide validation data for numerical simulations performed at the Centre of Compressible Multiphase Turbulence at the University of Florida. Five explosive tests were performed. Approximately 2.8 g of PBX-9501 was initiated by a RP-80 detonator. A 13 x 6 mm cylindrical packet of 100 μm steel particles was dispersed by the explosive. Three ambient carrier fluids were investigated: air, xenon, and SF6. To penetrate the optically opaque explosive products at the early time and track the dispersed particle cloud, radiography was required. Proton radiography performed at the Los Alamos Neutron Science Centre allowed extraction of 21 radiograph images at 2 μs temporal resolution. Upstream and downstream particle fronts were extracted from the transmission radiographs. Centreline particle fronts for the three carrier phases demonstrated close agreement, suggesting the shock traversing the bed of particles provided little additional impulse to the dispersed particles in this regime. An additional shot was performed in vacuum and showed close agreement with the carrier phase shots, furthering this conclusion.