From: Jed Rothwell
Sez who? Did they look for helium? As far as I know Mizuno does not have a mass spectrometer that can distinguish helium from D2. I will ask him if they looked for helium. Apparently you did not read it carefully. He does not need to distinguish helium from D2. He states that at the end of the run there was almost no mass-4 species at all! This indicates that most of the deuterium molecules were depleted and no helium was formed. Virtually all the gas was mass-2 at the end and there were about twice as many molecules as at the start - which indicates either H2 was formed from deuterium, possibly in some strange kind of beta decay, or else fractional-deuterium was formed (which can be stable as an atomic species). IOW – The original deuterium has either been converted to protium, or else into fractional-deuterium ions - what Mills would call deuterium-deuteride, but it has not fused to helium since there was no mass-4. Jones

