From: jac@ds8.scri.fsu.edu (Jim Carr)
Newsgroups: sci.physics.fusion
Subject: Re: D+D:Mother of all discoveries
Date: 29 Jul 92 20:29:39 GMT
Reply-To: jac@ds8.scri.fsu.edu (Jim Carr)
Organization: SCRI, Florida State University

In article <IeRMsym00UhB83IXpS@andrew.cmu.edu> pk03+@andrew.cmu.edu (Paul Karol) writes:
>
>It's been several days since I asked for a brief explanation of what the
>D + D --> He + gamma scheme is all about.  I got two responses.  One was
>a request that if I got any responses, please forward a copy.  The other
>was a statement that it's a crock and why was I wasting my curiosity (my
>paraphrasing).  

I have been too busy to formulate a complete reply, so I was hoping to 
see one and spare me the effort.  At the risk of being incomplete ....

d+d has three fusion paths: He-3 + n, H-3 + p, and He-4 + gamma. 

The branching ratios are basically 0.5, 0.5, tiny (I do not recall the 
value for the gamma branch, but many orders of magnitude down because 
of selection rules) so no one expects to see the gamma branch.  If it 
is there, it is easy to identify because there is not much background 
for 20+ MeV photons.  It has been looked for and not seen. 

Ying describes something that *is* stimulated emission cast in a funny 
(non-standard, but clear) language.  The idea is that the presence of 
either the gamma or the He-4 (or both) would stimulate the emission by 
enhancing the probability for the reaction.  As I speculated and someone 
here worked out, unreasonably high radiation levels are required for this 
to occur according to the rules of stimulated emission.  Further, the 
energy should come out in observable -- and dangerous -- radiation. 

A problem for this picture is that Ying used a gamma source that produces 
low energy gammas; not gammas of the same energy as the ones he wished 
to stimulate, as the theory requires.  He did use an alpha source that 
might produce alphas of a reasonable energy in the apparatus, but the 
intensity would still be low compared to what the theory requires.  (This 
is the theory that lasers are built from, so it is pretty well understood 
by that experimental/technological community.)  His apparent health 
argues against his own claims.

Thus his model is not wrong, but seems implausible as an explanation until 
one can see some products other than heat.  If there is stimulated emission 
of gammas, he should be able to detect gammas in proportion to heat!  If he 
can do so, this would be a major breakthrough.  Lacking them, one is forced 
back into the old problem of how to couple the fusion reaction to thermal 
energy without radiation (the Hagelstein-like phonon lasers) and how to 
detect He-4 products in the presence of background He-4 -- and where are 
the X-rays from recoiling He-4 nuclei?  These pictures do not seem to 
require stimulated emission of gammas, but their study would be helped 
if one had an experiment that worked on demand.

For me, the key is whether it is a perfectly reproducible, heat-producing
experimental protocol.  If so, then one can proceed to study it. 

--
J. A. Carr                                    |  "The New Frontier of which I  
jac@gw.scri.fsu.edu                           |  speak is not a set of promises
Florida State University  B-186               |  -- it is a set of challenges."
Supercomputer Computations Research Institute |   John F. Kennedy (15 July 60)
From: alexa@hpnmdla.sr.hp.com (Alexander Anger)
Date: Thu, 23 Jul 1992 22:33:05 GMT
Subject: Re: Does Cerencov radiation make sense?
Organization: Hewlett-Packard, Santa Rosa, CA