Evaluation of Explosively-Driven Flash Coatings

The application of flash coatings to detonation tests for light enhancement with high-speed imaging is a well-established technique within the community. From quickly assembled tests that use cigarette paper or even sand to nano-size particles suspended in a working fluid that is subsequently airbrushed onto samples, each group has created their own standard for what works best. These standards have remained in the background of many research studies that simply note a flash coating was used with little technical specifications or details given. Though one or two studies exist on the introduction of a new coating, information on how the morphology, application, and material type affects explosively-driven light output has been practically nonexistent. A review of past applications has yielded little information as many researchers who use flash coatings will state, "it's more of an art than a science." This work seeks to review non-reactive flash coatings that have been stated to work with a focus on aluminum oxide to investigate the effect of coating thickness and particle size. Streak camera imaging will be used to measure flash coating performance. Additional simulations using CTH will investigate how the coating material EOS and particle morphology affect temperature rise time, and will be used for comparison with experimental results.