Proton radiography and accurate density measurements: A window into shock wave processes

Direct density measurements were made from shock-loaded aluminum and copper samples by combining plate-impact experiments with proton radiography at the Los Alamos Neutron Science Center. Flyer plates were accelerated using a 40 mm bore powder gun to create a shock wave in a sample. The sample material was then interrogated in real time using the proton radiography facility. The increase in density behind the shock front causes a measurable change in the transmission of protons through the sample, which can then be quantified as a density value in the material. Hugoniot values were calculated using more traditional techniques to evaluate the accuracy of the radiographically obtained density measurements.