1. Physicist Claims First Real Demonstration of Cold Fusion

Comment #187865 by fynbo on June 2, 2008 at 10:29 pm

Sorry everyone : it seems I was somewhat too fast in my little physics lesson earlier :-{

Indeed there is a large probability that neutrons (and helium-3) are emitted in the fusion of two deuterons. The reaction I described is more rare.

I in any case doubt this is really fusion since I have not seen an explanation of what should bring the two deuterons close enough to each other for fusion to happen with large enough probability. In the sun the reaction is extremely rare, but enough energy is generated due to the large amount of material.

Wikipedia has a nice discussion on cold-fusion: http://en.wikipedia.org/wiki/Cold_fusion

2. Physicist Claims First Real Demonstration of Cold Fusion

Comment #187639 by fynbo on June 2, 2008 at 12:08 pm

As a nuclear physicist I have to correct some of the above misunderstandings : Fusion is NOT always accompanied by neutrons - that depends entirely on which reaction is going on. In the reaction claimed to happen in this story two deuterons fuse to helium-4 and nothing else. Each deuteron has one proton and one neutron, while the helium-4 has two protons and two neutrons. In the fusion reaction planned for hot fusion in the future fusion reactors the reaction is between deuterons and tritons leading to a helium-4 and a neutron. Secondly, even if neutrons had been present that would not directly have the consequence that people in the room would die - for that the dose rate has to be very high.