Abd Ul-Rahman Lomax wrote:
How many neutrons do You personally expect from D-D fusion? 1/event, 0.001/event or even less?
(Or bettter look up the figure...)
Personally? 0.5, it's well-known and easy to remember, so even though I'm 72, I don't need to look it up at all. The normal excited 4He* nucleus is highly unstable and has two basic ways to split, well known. The settling as an intact 4He nucleus is extremely rare, and this is all reasonably well understood.
Could there be some flaw in this? Yes. Maybe. But I don't expect it.
What I expect, from the evidence, is that the FP reaction is not "D-D fusion." I usually state it as "deuterium conversion to helium," and often add, "mechanism unknown."
As to the rate of neutron formation vs helium formation, neutrons have never been correlated with heat; however a rough rule of thumb is that tritium (also not correlated, or weakly correlated with heat) is down a million times from helium and neutrons are a million times down from tritium.