Performance of momentum diagnostics when impinged with a high-speed jet of explosive products

Characterization of jets of high explosive products is challenging. To work towards their measurement, a series of small-scale experiments was performed at Los Alamos National Laboratory to examine the performance of momentum diagnostics when impinged with a high-speed jet of explosive products. The experiments were driven by a 12.7 mm x 12.7 mm pellet of PBX-9501 initiated by an RP-1 detonator. Directly in contact with the high explosive was a 40 mm x 3 mm metal disk with an 800 μm hole located in the center. Upon detonation, this hole resulted in a high speed jet with a velocity of approximately 7 km/s. Several metals were investigated, including brass and tin, to determine the ability of the momentum diagnostics to detect ejecta while being subjected to the jet. A photonic Doppler velocimetry (PDV) probe was located directly in the path of the jet. Arrayed around the central PDV probe, were additional PDV probes and other momentum diagnostics such as piezo-pins and assay foils. Additionally, the jet was characterized by high-speed imaging and X-ray radiography. Results show that while the central PDV probe was destroyed by the jet on impact, neighboring probes survived the high-speed shock. The neighboring probes penetrated the explosive products and interrogated the surface of interest, even though they were separated by only a few millimeters from the central probe.