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Path: santra!tut!draken!kth!mcvax!uunet!husc6!mailrus!ames!hc!lanl!opus!dante!ted
From: ted@dante.nmsu.edu (Ted Dunning)
Newsgroups: sci.chem,sci.research,sci.physics
Subject: cold fusion report
Keywords: more report on pons' talk in utah
Message-ID: <188@opus.NMSU.EDU>
Date: 3 Apr 89 01:32:27 GMT
Sender: news@nmsu.edu
Followup-To: poster
Lines: 318
Xref: santra sci.research:664 sci.physics:5686
I was able to attend the pons lecture in utah in the main hall. i also
discussed the lecture with a number of people afterwards and have
the following impressions/corrections to the original posting in sci.physics.:
Electrochemically Induced Fusion
By Dr. B. Stanley Pons
Dr. Pons began with a brief history of the work began by he
and Fleischman. Initially, their interests were in the
development of a metallic hydrogen material for use as a
semiconductor. They realized that immense pressures were
required in a lattice for this to occur. However, they
theorized that it would be possible to bring about the
equivalent of this immense pressure by electrochemical
methods. From these initial musings, they also considered
whether this "electrochemical pressure" could be used to
fuse like nuclei (deuterium).
The initial experiment used a cube of Pd (size not stated)
in D2O at high current density (again not stated). A Geiger
counter was used to detect any radiation from the fusion
reaction of D. However no radiation was detected. The
experiment was discontinued by reducing the current density,
and shortly thereafter (overnight I think is what he said)
the experimental apparatus was vaporized. Left
approximately 1/10 of the initial Pd.
the cube was 1cm3. the experiment consisted of running
the electrolysis at 250 ma / cm2 for several weeks/months with no
results. the current was cut to 125 ma / cm2 late one day, and the
next morning the cube of palladium and the electrolysis cell were gone.
a nearby geiger counter was also ruined. pons used the word 'vaporized'
several times, but i wonder if what happened is really just that the pd
melted, and consequently could no longer hold hydrogen. at the density
quoted (1 atom D for each atom Pd), this would cause, at the least, a
vigorous mechanical explosion, and much of the molten palladium would be
spattered, if not atomized.
since no detailed calorimetric data was kept for this experiment (and
apparently the remainder of the cube is also not available), it is
only tantalizing, and cannot be used in any way but anecdotal. it is
true that the chemical energy contained in the hydrogen saturated cube
was not sufficient to even completely melt the cube, it is not clear
that the reaction was not caused by boiling some part of the electrolyte
with attendant local heating, melting and mechanical/chemical exploscion.
this is, however, perhaps the most viscerally interesting story released
so far.
the current apparatus uses pd rods of varying diameters from 1mm to
5mm. pons stated that work had also been done with larger diameters.
the electrolyte is 0.1 M lithium deuteroxide formed by dissolving the
pure metal in the d2o (to avoid h contamination). precharge time
is on the order of weeks for rods of this size.
Current apparatus uses a Pd rod in 0.1M D2O in a cell which
has been widely seen in the media. It consists of a Pd rod
surrounded by a Pt coil in a special made glass container.
There are openings for charging and adding D2O, measuring
temperature, and heaters. The use of rod gives better
control of the surface to volume ratio. During electrolysis
of the D2O the following reactions take place:
D2O + e- <---> Da + OD-
Da <---> Dlat
Da + D2O + e- <---> D2 + OD-
where Da is deuterium adsorbed on the surface of the Pd rod,
and Dlat is deuterium diffused into the lattice of the Pd.
Before the surface of the electrode is saturated with Da,
the D diffuses into the lattice of the Pd. The evidence
suggests that the deuterium diffuses into the lattice as
deuterons and electrons. The electrons go to the k band of
the lattice.
Dr. Pons stated that the potential of this electrochemical
couple is 0.8V. In terms of pressure to get the same degree
of difference in chemical potential = 10**27 atmospheres.
it is of course impossible to attain such physical pressures in pd, where
physical strength of materials would limit the pressure to approximately
4000 atmospheres. the figure of 10**27 if the equivalent pressure needed
(assuming van der wahls gas) to attain this electrochemical potential. one
possible reason that this effective pressure can be attained without serious
problems because the electrons from the D are also in the lattice, although
they are separated from the deuterons.
there is also considerable doubt on the part of several electrochemical
experts i have spoken with on this matter. they state that without
careful poisoning of the surface of the palladium, it is difficult to
achieve such electrochemical potentials. there was no mention of special
surface treatment in pons talk, and it is very difficult to avoid considerable
contamination of the surface.
Dr. Pons explained a control experiment where they used a
closed cell to detect tritium (else some tritium would be
lost as by exchange with D2O). Tritium was detected, and
its concentration increased over time. Also the neutron
flux was measured as 10**4 n/s. This is 3X higher than
tritium detection was by sampling the electrolyte and determining a beta
spectrum. the energies of the betas indicated tritium. the neutrons
were detected using a harwell detector as well as by detecting secondary
gammas from the surrounding light water bath. gamma spectra indicated
a clear peak at 2200 KeV. unfortunately NONE of these measurements weree
corrected back to specific source intensities. it is also not clear that
the tritrium measurements were not considerably in error due to residual
tritium trapped in the palladium.
background and was considered statistically significant.
However, the reactions to produce tritium and 3He do not
explain the amount of heat produced.
no detections of He3 were possible since the solubility is so low. the
detection of on the order of 10**4 to 10**6 atoms of a non radioactive
gas is non trivial. apparently they have done some preliminary mass
spectroscopy. anomalously, he4 WAS detected. the D-D fusion which
produces He4 + gamma is normally very rare. the gamma has a 15-17 Mev
energy which is considerably outside the range shown on the spectrum
in pons talk.
In this same vein, he pointed out that their experiments
indicated that the heat produced was proportional to the
volume of the electrode used, not the surface area of the
electrode. This indicates that the process is not
electrochemical in nature. An energy density of 26W/cc of
electrode was calculated. One experiment produced 4MJ of
heat in 120 hours. He reiterated that this could not be due
to any known physical or chemical process. Since the fusing
of deuterium is only part of the overall reaction scheme,
other as yet unknown processes produce the rest of the heat
which is detected. Dr. Pons believes these unknown
processes must be nuclear processes.
unfortunately, as was made clear by the cluttered table momentarily shown
during the talk, the highest power density was acheived at high current
densities, while the best efficiency was attained at low current densities.
no mention of temperature coefficients was made. also, the higher
efficiencies were only extrapolated assuming recovery of the energy due
to recombination of the electrolysed oxygen and deuterium.
He also surmised that the deuterons existed in the Pd
lattice as a low temperature plasma which is shielded by
electrons.
Dr. Pons then answered several questions from Faculty
members (there were no microphones in the room with the
graduate students where I was). The content of his
responses are summarized below.
This reaction is diffusion controlled, with the diffusion
this is unfortunately inconsistent with the pre-charge times quoted.
of course this figure is for diffusion in the alpha state, while the
deuterons are in the beta phase. pons stated that he expected the
diffusivity to be nearly equal for both phases, but that he had not
confirmed this.
coefficient for deuterons in Pd given as 10^-7 cm^2/s.
others have said that this is a very conservative figure and that
diffusion at a poisoned surface would likely predominate.
The production rate of tritium was found to match that of
the neutrons.
as mentioned above it is very doubtful that this conclusion can be reached.
this would be very significant given the expected cross sections for the two
dd fusion reactions at higher temperatures.
Although the cross-section of Pd is too small to allow for
significant reaction with energetic neutrons, it may react
with neutrons back-scattered from the heavy water. No assay
of the Pd electrodes has been undertaken to check for
activation by-products of Pd.
no assay has been completed. pons stated that he has sent several of the
electrodes out for testing. the mean free path of 2.5 MeV neutrons in
heavy water is about 20cm, which combined with the low density of neutrons
should preclude detectable residual activation of the palladium.
The ignition/vaporization of the initial experiment was
caused by a steep concentration gradient of D+ as the
current density was decreased. This gave rise to
compression (even greater than *normal*) as the D+ species
moved out from the lattice in a radial direction. This
"shock" resulted in the vaporization.
this is COMPLETELY hypothetical at this point. the formation of a shock
in a diffusion situation is also unbelievable. this shock should also
be formed when the current is turned on, but that would contravene the
observed pre-charge phenomenon.
No 2.45Mev neutrons were detected. He speculated that these
neutrons may be consumed by reaction with Li:
7Li + n + 2.45MeV ---> 3T + 3He + n
6Li + n ---> 3T +3He + 4.5MeV
the pertinent cross section of lithium in the electrolyte for this
reaction is MUCH to low for this happen
The concentration of the deuterons in the Pd lattice is
greater than 0.67 (deuterons/Pd atoms) and is estimated to
be 1.0 - 1.2. They are believed to cluster at the
octahedral sites in the Pd (Pd has a face centered cubic
crystal structure).
In looking for products of fusion, 3He was not seen but 4He
was. Part of the reason for not seeing 3He is due to the
apparatus used (apparently not very airtight) and
instruments used.
see above comments. even if the apparatus is airtight, this many atoms
would be extraordinarily hard to find.
Other metals (which were not specified) were tried as
electrodes but no heat was detected. Radiation was not
monitored.
No experiments have been carried out in magnetic fields to
determine quadrupole effects. He admitted that spin-spin
interactions could have an effect.
The reaction is diffusion controlled. In a 0.4 - 0.5mm rod
with X=10^-7 cm^2/s, the time required to start the reaction
is [ (0.2)^2 / X ].
this does not jibe with the announced pre-charge times. we should also
be watched for a precharge time dilation effect (i.e. as the amount of
time without confirmation increases, the pre-charge time may also be
observed to increase, apparently without bound. this is a p.r. effect).
:-)
He did not know the effective mass of the electron carriers
in the Pd matrix.
the snide comment here was that he 'hoped that it is about 200'. this
refers to the possibility of heavy electron catalyzed fusion similar to
muon catalyzed fusion. this is not possible since the heavy electron
effect is due to electrons hauling lattice disturbances along with them
when traveling free in a metal lattice. the point of muon catalyzed fusion
is that since a muon is so much more massive than an electron, the effective
diameter of a muon containing atom is much less than for a normal atom.
if the deuterium exists in pd as a plasma, then this effect would not
be pertinent.
He felt that the addition of hydrostatic pressure to the
cell would have a negligible affect on the rate of the
reaction. The potential gradient at the D2O Pd interface is
on the order of 10^12 V/m. This gradient can not be
achieved in gas or vacuum phase conditions.
this has implications regarding both the pumping of D into the pd lattice
and ionization of the D.
They have recently achieved a 1W in 10W out energy ratio.
these energy ratios are extrapolated after assuming that a fuel cell
anode is used to recombine the evolved deuterium. actual power out/
power in is about 1.11 . considerable amounts of energy are stored as
separated heavy water.
Essentially no neutrons or tritium are detected until the
fusion process begins.
He jokingly predicted that 100 years would be needed to
bring this technology to commercial use.
He admitted that the results were just as puzzling to him as
they are to many others. He openly admits that much more work
is needed to understand this phenomenon. (He did not seem to
resent any questions, and was honest in his responses.)
He ended his talk with a WARNING. Please do not DO NOT
attempt to repeat this experiments until you have read the
journal articles or have consulted with Drs. Pons or
Fleischman directly. The initial experiment which vaporized
is no joke. Please consult with them or wait for the
articles to appear before you begin a possibly dangerous
experiment. Please act responsibly in this regard.
in particular if you try this, avoid
a) large electrodes
b) sharp corners
c) powdered electrodes
d) sharp changes in current
e) extremely high current densities
f) experiments with D-T or T-T reactions
the reason for the last is that these reactions are expected to occur
10**3 or 10**4 times more quickly than D-D reactions. 10**4 W/cm3 is
very dangerous.
if you are trying these experiments, careful calorimetry and accounting
of evolved gases must be done. just running an open cell without good
heat flow measurements is worthless. keep neutron and gamma detectors
handy and treat the experiment as a low grade radiation source and a
serious chemical hazard at the same time. be ready for radiation flashes
and chemical or other small scale explosions. no data yet exists indicating
that dangerous levels of radiation will be observed, but there is no sense
in being a famous dead person. still less in being a kind of famous near
dead bald person.
pons and fleischman paper will be publised soon in the journal of
electroanalytical chemistry. i have reason to believe that the contents
of the paper will not answer many questions that his seminars will not.