ISIS Report 23/10/07
How Cold Fusion Works
Many ways for atomic nuclei to come close coherently and fuse together in
condensed matter. Dr. Mae-Wan
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Cold fusion with ease
The surprising thing about cold fusion is how easily it could be made to happen,
and in many different forms [1, 2] (see From
Cold Fusion to Condensed Matter Nuclear Science and Transmutation,
the Alchemists’ Dream Come True? SiS 36). This is in striking contrast
to hot fusion, which requires temperatures of millions of degrees K.
The key to cold fusion is
that it happens in condensed matter. Simply put, there are many ways for nuclei
to come together coherently and fuse in condensed matter. Cold fusion is friendly
fusion, and does not need to be forced by thermonuclear temperatures.
First of all, the hydrogen
or deuterium nuclei are trapped in the host lattice, and hence much closer
together than they would otherwise be in the gas phase. Under these conditions,
quantum effects take over. Energy levels are no longer discrete; instead,
they merge into broad bands. Coherent vibrations of the trapped nuclei, the
electron cloud and the host lattice interact, all of which conspire to let
nuclei slip under the Coulomb barrier and fuse together.
Delocalised and overlapping wave functions in condensed matter
Retired physicist from the US Naval Research Laboratory Talbot Chubb describes
cold fusion as using a “catalysed configuration” to replace the need for high-energy
collision between particles in hot fusion .
In the typical experiments where deuterium is absorbed
or generated in a palladium electrode, the deuterons (nuclei of deuterium)
become delocalised as waves with periods of the host lattice; this is referred
to as a ‘Bloch state’. Bloch states enable the waves of different deuterons
to overlap, and at a certain point when the kinetic energy of the vibrations
becomes greater than the potential energy of the Coulomb barrier, the latter
becomes irrelevant and two deuteron waves fuse into one. The electrons will
also be delocalised as Bloch waves and will serve to shield the like charges
of the nuclei and enable them to come closer together, thus facilitating the
Two deuterons fusing together
gives helium-4 and excess energy of 23.8 MeV. The excess energy is transferred
to the host lattice as phonons (sound waves) and dissipated as heat. This
could explain the results of many cold fusion experiments, including that
of Fleishmann and Pons  that started the whole field.
However, it was already
apparent in the Fleishmann and Pons experiments that excess heat was produced
in at least two ways: a predictable steady state (when helium-4 could well
be produced), and unpredictable bursts of intense activity associated with
the production of tritium.
Electron capture for nuclear transmutation
Allen Widom at Northeastern University Boston and Lewis Larsen of Lattice
Energy have recently proposed a mechanism that could account for a wide range
of fusion and transmutation reactions, electron capture by protons or deuterons
In nuclear physics, it is
very well known that a proton can capture a negatively charged lepton (light
particle) and produce a neutron and a neutrino, and a common form of nuclear
transmutation in condensed matter can be understood in term of this reaction.
An electron that wanders
into a nucleus with Z (atomic
number) protons and N (= A (atomic mass) – Z) neutrons can be captured, producing a
neutrino and leaving behind a nucleus with Z-1
protons and N+1 neutrons. There
is no Coulomb barrier in this process, which makes it much more likely than
other reactions. In fact, a strong Coulomb attraction between an electron
and a nucleus favours electron capture for nuclear transformation.
While lepton capture is known to occur in the case of muons
(leptons) mixed into hydrogen systems, it is regarded as difficult for electrons
to be captured by protons. For the reaction to happen, the lepton must be
sufficiently massive, such that in energy terms, Mlc2 > Mnc2-Mpc2 ~ 1.293MeV ~2.531Mec2
Mn, Mp, and Me are the mass of the lepton,
neutron, proton and electron respectively, and c
is the speed of light). The muon is more than sufficiently massive to be captured
by the proton, but not the electron, which needs to be at least 2.531 times
However, the electron mass in condensed matter can be modified
by local electromagnetic field fluctuations. For example, laser light fields
can “dress” an electron with additional mass. The surface states of metal
hydrides are very important in this respect.
Collective surface oscillations
of charged ions are involved in the weak interactions responsible for electron
capture in condensed matter. The radiation frequencies of these oscillation
range from the infrared to the soft X-ray spectra. The surface protons are
oscillating coherently, contributing to the large magnitude of electromagnetic
fluctuations. The neutrons produced by electron capture have an ultra low
momentum (with long wavelength) due to the size of the coherence domain of
the oscillating protons, estimated to vary from about one to ten microns in
length. The long final state neutron wavelength allows for a large neutron
wave function overlap with many protons, which increases the coherent neutron
It is estimated that the electron mass enhancement due to
the electromagnetic field fluctuations (collective proton oscillations) on
the surface of palladium hydride is about 20.6 fold, which is much more than
enough for electron capture by proton or deuteron. The proton field oscillations
can be amplified by shining a laser light on the palladium surface, which
can enhance the production of neutrons that in turn catalyse other reactions.
The neutron, n, can fuse with other nuclei in transmutation
reactions. Lithium (Li) is present in the electrolyte. A Li ion near to the
hydride (electrode surface) could initiate a chain of reactions as follows:
6Li3 + n → 7Li3
7Li3 + n → 8Li3
8Li3 → 8Be4 + e- (electron) +v (neutrino)
8Be4 → 4He2 + 4He2
Q ~ 26.9 MeV
A large amount of energy, 26.9 MeV is generated by this chain of reactions.
Having produced 4He2,
further neutrons may react to build heavy helium isotopes, and regenerate
Li as follows.
4He2 + n → 5He2
5He2 + n → 6He2
6He2 → 6Li3
+ e- + v
Other possibilities include direct lithium reactions
6Li3 + n → 4He2
3H1 → 3He2
+ e- + v
Q ~ 4.29 MeV
These examples show that a final product, such as 4He2,
does not necessarily constitute evidence for the direct fusion of two
deuterons, which requires tunnelling through a high Coulomb barrier (see above).
More importantly, final products such as helium-3 and tritium are also possible,
as have been detected in many experiments.
Widom and Larsen are latecomers to the cold fusion field, and it is not clear
to what extent their theory is accepted. I find it quite convincing especially
for the low energy transmutation of elements , though it doesn’t necessarily
exclude other mechanisms that depend equally on quantum coherence.
Krit Prasad Sinha and Andrew Meulenberg at the Indian Institute of Science
Banagalore, India, propose the formation of deuteride or hydride (D-
or H-) ions due to interactions of the deuterium or hydrogen with
the phonon vibrations of the host lattice. ‘Local charged bosons’ (lochons)
or local electron pairs can form on D+ to give D- [5-7].
At the same time, the collective
motion of the deuterons driven by the phonons can introduce ‘breathing’ modes
in the Pd lattice. If these breathing modes are resonant with the deuteron
motion, they enhance deuteron migration and the rapid refilling and regeneration
of the active sites. If the resonant vibration is anti-phase, the Pd atoms
could move apart as adjacent deuterons come together, thus allowing direct
collision of the deuterons while
an electron cloud helps screen the repulsion due to the deuterons’
The formation of D- reverses
the normal electrical repulsion between D+ ions,
as D- and D+ can attract each other. The D+D-
equilibrium positions in the lattice are much closer together than in free
molecular D2 because of the increased effective electron mass from
phonon interaction, reducing the electron distribution size into the sub-nanometre
range, and therefore the point at which the attraction begins to diminish.
The paired D+D- system has a much reduced zero-force
distance (~2 nm) relative to that of a D2 molecule (~7 nm). All
that conspires to increase the probability of fusion.
The D- and D+
fuse to form 4He2 releasing a large amount of energy,
23.8MeV, which is carried by the alpha particle and the ejected electron pair.
Sinha and Meulenberg calculated a reaction rate of about 1.5 x1011
s-1. This is comparable to the muon-catalysed reactions giving
tritium plus proton (T + p) or 3He + n processes (see previous
This mechanism too, could
be greatly enhanced by laser stimulation.
Selective resonant tunnelling
In November 1989, the Energy Research Advisory Board of the Department
of Energy in the United States made five recommendations, among
them, to check for excess tritium
in the electrolyte in which cold fusion was supposed to have occurred. However,
the amount of tritium generated did not tally with neutron emission. The expected
14 MeV neutron was not detected.
But tritium has appeared since in experiments in Japan,
Italy, Russia, USA, Canada, India and China, and according to Li Xing Zhong
at Tsinghua University Beijing China, it is one of the strongest pieces of
evidence for condensed matter nuclear reactions, as it implies a new mechanism
operating at low energy: selective resonance tunnelling .
A harmonic circuit is able to
pick up the specific frequency from the air, but when the signal is weak,
the resistance of the circuit must be low. It is the same with
resonance tunnelling of the Coulomb barrier. At low energy, the Coulomb barrier
is thick and high, hence the incident deuteron wave in the nuclear well is
very weak. The amplitude of the
weak penetrating wave may be enhanced by the resonance effect
when the phase of the reflected wave inside the nuclear well is the same as
that of the incident wave. This is resonant tunnelling. The damping must be
weak, which is due to the fusion reaction itself, because the deuteron wave
function disappears on fusion. Thus, this fusion reaction rate cannot be very
fast, or it will kill the resonant effect. On the other hand, the rate cannot
be too small, or it will give no fusion. As a result, the life-time of the
deuteron wave function cannot be too large or too small. There is an optimum
match a specific Coulomb barrier:
q is a very large number for a thick and high
Coulomb barrier, of the order of 1022 to 1031 or greater
is the ‘Gamow penetration factor’, the kinetic energy of the approaching nuclei
relative to the energy of repulsion between the nuclei); tflight is the flight time
inside the nuclear well for the penetrating deuteron, and is of the order
The reason there is no neutron
emission from resonant tunnelling at low energy is because the lifetime for a neutron emission process
is too short at around 10-23 s. Only the weak interactions
loss or gain of electron) might possibly
provide the lifetime necessary.
Thus, selective resonant tunnelling provides the mechanism
for penetrating the Coulomb barrier, and its selectivity explains why there
are no neutron or gamma radiations after the resonant tunnelling at low energy.
If weak interaction is the only possible reaction
s for the resonant tunnelling
at low energy, the possible reactions are between a proton p and a deuteron
p + d → T + e+ (positron) + ne
p + d → T + ne
Usually the positron decay is faster than k-capture, the capture of an
electron. In the case of resonant tunnelling, positron decay is too fast to
meet the matching condition, so only
is possible. This is consistent with experimental results. The annihilation
of positron would produce 0.511MeV gamma radiation. But this is not observed
in any tritium production experiments. The hydrophilic nature of the heavy
water might explain the contamination by light water in the electrolytic cells,
and that would be the source of protons for the resonant tunnelling reactions.
Solid state provides an energy band for deuterons or protons,
thereby increasing the possibility of overlap with the resonant tunnelling
state. Certain metals (Pd, Ni, Ti etc.) are particularly good because of their
ability to absorb hydrogen, thereby filling this energy band to capacity.