There are UVA flashlights with insane output already in existence. Cree does not make UV but Nichia does and has some of the best 365nm high-output LEDs out the

There are UVA flashlights with insane output already in existence. Cree does not make UV but Nichia does and has some of the best 365nm high-output LEDs out there with some of the lowest visible light output/generation. Another contender is Prolight. I have one of their 60 degree UVA LEDs in a light I use for mineral exploration, it will make things glow from almost 50 feet out, but it also has some considerable visible light generation that interferes with detecting weaker fluorescence. If you want a HUGE UVA bank, look at Wild Fire. They make UV LEDs for party places, like cosmic bowling nights, and such. One of those could likely be easily adapted to your purpose, though it might be a little pricey.