From: M21742@mwvm.mitre.org
Newsgroups: sci.physics.fusion
Subject: Re: Secondary x-rays as nuclear evidence
Date: 9 Oct 92 14:58:18 GMT
Organization: The MITRE Corporation, McLean VA 22102

In article <11024@sun13.scri.fsu.edu>
jac@ds8.scri.fsu.edu (Jim Carr) writes:
 
>
>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
**************************************
Dick Forman apoligizes to netters for lack of cleanup and deletions.
     But:  If you look at some of my papers with Chuck Bouldin on x-ray
fluorescence detection you will note this is a nasy field.  There is so-called
near edge structure called a white line that can mess up all naive guesses
on what radiation comes out. Remember that the secondary x-ray is a line at
some unknown energy. Two points: the terminology secondary x-ray is incorrect,
the energy is "unknown" on the scale of eV out of keV.
 
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RICHARD A. (DICK) FORMAN AT MITRE IN MCLEAN, VA  (703) 883-6198
DISCLAIMER: MY OPINIONS ARE MY OWN NOT MY EMPLOYER'S.