a r7s-socket uv-lamp, which should fit into a cheap flood light (not closing the glass cover it came with, to not add any uv-filtering, i guess). it costs about $20 and i'll pick one up soon and see how it prints.
there's a data sheet available (in english too), but there isn't much info apart from "emits strong uv-light in close proximity. take care". http://www.produktinfo.conrad.com/da...e_en_fr_es.pdf
That would work excellently. It's also hazardous of course, but we *are* trying to generate UV here. Clear acrylic (aka lexan or perspex) will block all the dangerous stuff.