Neutrons. If it is a cold fusion device (which the arXiv article does not claim), then copious neutron production is almost unavoidable. If I were evaluating s

Neutrons. If it is a cold fusion device (which the arXiv article does not claim), then copious neutron production is almost unavoidable. If I were evaluating something that claimed anything like nuclear power densities, you can be certain that I'd have radiation detectors around, and I'd write about it in my paper. This would be as much for my own safety as for science. A successful invention of an alternative energy source won't require secrecy. That's what a patent is for. It's not something that can be commercialized (or even produced in quantity) without someone tearing it apart and figuring out how it works.