From: jac@ds8.scri.fsu.edu (Jim Carr)
Newsgroups: sci.physics.fusion
Subject: Re: Secondary x-rays as nuclear evidence
Date: 6 Oct 92 18:19:23 GMT
Reply-To: jac@ds8.scri.fsu.edu (Jim Carr)
Organization: SCRI, Florida State University

In article <1992Oct5.172629.152@physc1.byu.edu> jonesse@physc1.byu.edu writes:
>
>                    ...                        The principle question seems to
>be:  "Is the heat due to nuclear reactions?"  (Tabelling for the moment the
>question "Is the heat real?")  

Agreed.  Otherwise, why would it be in sci.physics.fusion?  However, I 
do want to emphasize my view that a big part of the problem is getting 
a setup that provides heat reliably so that the products can be looked 
for in a controlled experiment.  It would be nice if Droege has such 
an experimental design. 

>3-  Combining points 1 and 2 - retaining generality in not specifying a
>particular nuclear reaction - we deduce that 1 watt of excess power requires of
>the order of a trillion reactions per second.
>4-  The primary products may hide, but at these rates, secondary X-rays cannot
>hide.
>5-  For instance, in palladium, the k-alpha x-ray has 20 keV, which is quite
>penetrating.  In heavy water, approximately 20% of these X-rays survive after
>40 mm.  The palladium is a better attenuator, but with either a volumetric or
>(better) a surface reaction, significant X-rays ought to get out:  a few
>percent survive 300 microns of Pd by montecarlo calculation.

Yes, and this has been looked for, and not found (Phys. Rev. C 40, 1851) 
in a cell of the FP&H type, although it is more likely the cell was also 
not producing heat.  When Robson and I were discussing this experiment 
(then in the planning stage) over breakfast at a conference, we were 
mainly concerned about self-absorption by the Pd.  This is probably 
compensated for by the fact that the characteristic energy helps you
pick them out from background.  At the time, the claim was that we 
should expect reactons on or near the surface.  We were also concerned 
that there could be shadowing of the detector if the reaction location 
depended in some unknown way on the anode/cathode arrangement. 

Of course, they were looking for PIXE x-rays from the proton in the 
p+t final state, so the range of the proton on Pd will act to spread 
the effective source size and reduce the significance of ones ignorance 
of the specific location of the reaction.  

>6-  MeV-energy charged particles produce excitations which lead to copious
>X-ray production.  My colleague Larry Rees estimates, for example, 3X10**-8 k
>x-rays per 3-MeV-proton.  With a trillion or a billion nuclear reactions per
>second, the 20 keV x-ray yield ought to be easily detectable.
>
>Have I missed something, or should secondary X-rays provide for a crucial
>experiment to determine whether the "excess heat" is in fact nuclear in origin?

I do not think so.  We lost interest in detailed model calculations when 
the experiment came up null and there were no indications that anyone 
could replicate the original work so better experiments would be worth 
the investment of our time in thinking about them.  

If Tom Droege finds that he can build a new cell that works just as 
well as his current cell, it might be time to take it on a road trip 
to some of the nuclear facilities that can look for these things.  Yale 
and Steve's mine shaft and the mini-ball at FSU could all be useful. 

Perhaps it is time to think real hard about nuclear reactions that release 
only a fraction of a keV and that might have a lower coulomb barrier than 
what we have considered so far.... 

--
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)
Newsgroups: sci.physics.fusion