Tesla's Radiant Energy

[Mozart]

You just don’t need to speculate, everything needed is already in the patent and works with all kind of energy form being radiated, including artificial sources. I am not going to suggest xrays as per Tesla patent, but a very high source of UV is a street lamp (old ones) on low pressure mercury vapour and they can be as little as 80 watts … we only need to eventually replace the reflector to focus on an aluminium plate or an amalgam of magnesium-aluminium-zinc-brass-mercury.

Or any low power lamps on low pressure mercury vapour that yield huge amount of UV.