High-Energy Radiography of a Dynamic Object Using Two Different Probe Modalities

Radiography of a dynamic object is a key diagnostic of experiments for shock compression of materials, high explosives, and hydrodynamics. These measurements are used to validate simulations and to obtain physical data. We hypothesize that significantly more information can be obtained from each single-shot event if radiographs are made with more than one kind of probe beam, e.g. x rays, electrons, protons, or neutrons. We are investigating the creation of these beams with high-intensity, short-pulse lasers due to their flexibility and efficiency. Experiments at the Omega EP laser facility have established proton beams with energies >75 MeV and x-ray beams with endpoint energies >2 MeV using known mechanisms. X rays and protons were used, separately, to take radiographs of both static and dynamic objects. The sources were used to radiograph a static object simultaneously. To create a dynamic object to radiograph, a halfraum driver needed to be developed due to the geometry of the EP laser beams. This gold halfruam is driven by two long-pulse, 4 ns, beams with 6.8kJ of laser light. The drive was characterized by measuring the shock speed driven though several different packages and measured by VISAR. In this way, a simulated drive with a radiation temperature of >140 eV was created and used to simulate the drive through a physics package. Static radiographs of the package and background measurements are also complete. In May 2025, dynamic experiments were attempted.