A tomographic UV-sheet scanning technique for producing 3D fluorescence images of x-ray beams in a radio-fluorogenic gel

In this work a 40 mm cube of an optically clear, radio-fluorogenic gel composed of partially-polymerized tertiary-butyl acrylate and maleimido-pyrene (~0.01%) is irradiated with orthogonally-crossed, 10 mm square and round, 200 kVp x-ray beams. A thin sheet of UV light is produced between two parallel plates with 2 mm slits illuminated by collimated, linear-array, LED sources. The gel is transported 1 mm at a time through the UV sheet and the fluorescence from the emissive, polymeric radiolytic product formed in the x-ray tracks is recorded, as both JPEG and raw-DNG files, using a CCD camera placed orthogonal to the plane of the excitation light. The resulting stack of 40 tomographic slices are imported into freely-available software to produce 3D animated images of the radiation-induced fluorescence.