Path: santra!tut!draken!kth!mcvax!uunet!lll-winken!ames!xanth!mcnc!ecsvax!jrw
From: jrw@ecsvax.UUCP (James R. White)
Newsgroups: sci.physics
Subject: fusion theory
Keywords: fusion neutron theory
Message-ID: <6776@ecsvax.UUCP>
Date: 5 Apr 89 17:31:38 GMT
Organization: UNC Educational Computing Service
Lines: 77


     Normally I wouldn't bother posting my random theories on fusion,
but this theory seems to predict the runaway reaction that may have
occurred in the original experiment. It also suggests that an intense
burst of neutrons could occur during this reaction.
     I think someone has already suggested the basic idea. Consider
the helium atom. There are two electrons in the same orbital, even
though electrons repel each other. There is a certain probability that
at any given time the electrons will be found very close together. The
same thing can happen to hydrogen and lithium nuclei.
     Pd has a face centered cubic crystal structure. That is, place
an atom at each corner of a cube, and in the middle of each face.
There is a small hole in the center of this structure that can act
like a potential well. There will be one such well for every four Pd
atoms.
     If Pd is saturated with D, then there will be two D ions in each well.
These can either sit side by side, or they can both be in the same orbital.
Quantum wave functions have a lower energy if they spread out, so each D
would like to use the whole well. But the positive D ions also want to keep
away from each other. In the case of two D, the side by side seems to be
the lower energy state.
     If a sample of Pd with two D per well is hot enough, however, then
the higher energy state will occur in a significant number of wells.
This will lead to the D + D -> 3He + n and D + D -> T + p reactions.
These reactions could heat the sample, leading to more D being put in
the overlapping state. This can result in a runaway reaction producing
a burst of neutrons. It is possible that saturating Pd with D, and then
heating before the D can leak out will produce this effect.
     I assume there was no lithium in the first sample that vaporized,
so this may have been what happened. The "diffusion shock" might have
triggered this runaway reaction. I understand the background radiation
in the lab the next day was only three times higher than normal, so most
of these high energy neutrons must have gotten out and been absorbed
somewhere else. Were there any reports of premature hair loss from grad
students working late in other parts of the building?
     The lithium ion has two electrons around it, and so would fill the
well. These same electrons would mask the +3 nucleus. Thus, the H or D
may prefer to sit on top of the Li rather than be crowded into a corner.
The H ion would have the biggest aversion to being squeezed into a corner.
The overlapping state seems to occur at room temperature. If side by side
is still the lowest energy state, then increasing the temperature will
increase the reaction rate. But if overlapping is the lowest energy state,
then the rate will decrease slightly. This is because the lowest energy state
will be occupied at low temp, while all states will be equally occupied at
high temp.
     The main Li reactions are 6Li + D -> 4He + 4He and 7Li + H -> 4He + 4He.
Possible side reactions include 7Li + D -> 8Be + n and 6Li + H -> 7Be + gamma.
7Be has a halflife of 53 days, emitting a gamma at .4776MeV so it is easily
detected. 7Li + D can't be happening very much because there are so few
neutrons. I don't know why there should be 10**9 reactions of 6Li + D for
every 7Li + D, especially when there is 12 times as much 7Li as 6Li.
I think someone has suggested a 8Be excited state allowing 6Li + D -> 8Be.
Or perhaps Li and D sit side by side while Li and H overlap, so 7Li + H is
actually doing all the heat production (there would be some H contamination
in the D2O, and maybe in the Pd as well). Doing the experiment with H2O would
show whether 7Li + H was the heat producer. Using pure 6Li and 7Li could also
help show what is going on.
     Most of the lengthy precharge time is probably due to slow Li
diffusion. Can Pd be alloyed with Li without affecting the crystal structure?
One Li atom for every four Pd might virtually eliminate the precharge, since
every ion of H or D would have to sit in a well with a Li. Also, lack of Li
diffusion may be the reason other metals don't work. D and H will diffuse
through almost any metal at the elevated temperature of a commercial fusion
reactor. Any alloy with potential wells in its crystal structure and Li in
those wells would be a candidate. The alloy of one Li atom to four Ni looks like
a good thing to try.
     Using such a Li alloy might also be a good way to reduce those nasty D + D
reactions, as these probably don't occur in wells containing Li. Radioactivity
is not desirable in a nuclear reactor.
     Coating 99 percent of the surface with some insulating impermeable
substance would make things more efficient. It would reduce the current
required for maintaining equilibrium by a factor of one hundred. Precharging
could be done at high temp (where diffusion is rapid) using a suitable
high temp electrolyte (LiOH?).

Disclaimer: The above may have nothing to do with reality.
John N. White - jrw@ecsvax