Evaluating laser-driven Bremsstrahlung radiation sources for imaging and analysis of nuclear waste packages

A small scale sample nuclear waste package, consisting of a 28 mm diameter uranium penny encased in grout, was imaged by absorption contrast radiography using a single pulse exposure from an X-ray source driven by a high-power laser. The Vulcan laser was used to deliver a focused pulse of photons to a tantalum foil, in order to generate a bright burst of highly penetrating X-rays (with energy >500 keV), with a source size of <0.5 mm. BAS-TR and BAS-SR image plates were used for image capture, alongside a newly developed Thalium doped Caesium Iodide scintillator-based detector coupled to CCD chips. The uranium penny was clearly resolved to sub-mm accuracy over a 30 cm2 scan area from a single shot acquisition. In addition, neutron generation was demonstrated in situ with the X-ray beam, with a single shot, thus demonstrating the potential for multi-modal criticality testing of waste materials. This feasibility study successfully demonstrated non-destructive radiography of encapsulated, high density, nuclear material. With recent developments of high-power laser systems, to 10 Hz operation, a laser-driven multi-modal beamline for waste monitoring applications is envisioned.

"'Nothing but a printer's devil ever drives me into finishing': the Genesis of Thomas Moore's Irish Melodies'

This chapter outlines the working methods of the prolific writer and lyricist Thomas Moore—which were characterized by the unfortunate combination of a perfectionist streak, a tendency to release material to the publishers while still in the creative mode, and a tendency to re-visit previously-published material. The Gibson-Massie Moore collection at Queen's University Belfast teaches us a great deal about Moore’s creative processes, and also records the nineteenth-century publishing industry’s response to one of its most prolific and popular creative artists. This chapter is illustrated by an online Exhibition, the 'Thomas Moore Project', Digital Collections, Special Collections, McClay library (see URL below).