A pixelated BGO scintillator array for high energy ´flash´ radiography

Transmission X-ray radiography of dense objects plays an important role in AWE hydrodynamics (hydro) experiments. The most challenging of these hydro experiments is a flash radiographic technique known as ´core-punching´. This technique utilises a 100 ns burst of MeV photons to image a dense, explosively driven object. MeV X-ray flash radiographic imaging is typically characterised by a low signal fluence of the most penetrating energies i.e. 2-5 MeV. X-ray converter (i.e. the scintillator) characteristics dominate the detector performance in terms of both quantum efficiency and resolution. Requirements are for a high (X-ray) quantum efficiency (>20%) together with ∼1 mm spatial resolution. The design and construction of a large format pixelated BGO scintillator array, to meet this stringent requirement, is described.