Flash radiography studies with microcolumnar CsI

There is growing interest in using low-energy flash x-ray sources in radiographic applications to provide high-contrast images of low-density objects. Due to the low-energy nature of the detected photons, thin bright scintillators are desired. In order to pursue an optimum radiographic system, experimental studies have been performed of the static imaging properties of thin microcolumnar CsI using a Platts x-ray source. The Platts source is a nominally 300 keV endpoint rod pinch diode x-ray source with a ~35 ns pulse time. The source was used to measure the imaging properties of microcolumnar CsI with various thicknesses and backings. The experimental setup was modeled in GEANT4, and the images were simulated to estimate system performance. Taking into account the source photon production, radiation transport, and system optical performance, an accurate assessment of the detection system can be deduced.