[Ed. note: This is a March 14, 2007 review by Dr. Robert Deck of Toledo University of the four papers by Widom and Larsen listed below. For links to these papers online, see the publication list on our Widom-Larsen Theory page.]
#1 (March 9, 2005 ) "Ultra Low Momentum Neutron Catalyzed Nuclear Reactions on Metallic Hydride Surfaces" Eur. Phys. J. C (2006) THE EUROPEAN PHYSICAL JOURNAL C
#2 (Sept. 10, 2005) "Absorption of Nuclear Gamma Radiation by Heavy Electrons on Metallic Hydride Surfaces"
#3 (Feb. 20, 2006) "Nuclear Abundances in Metallic Hydride Electrodes of Electrolytic Chemical Cells"
#4 (Aug. 25, 2006) " Theoretical Standard Model Rates of Proton to Neutron Conversions Near Metallic Hydride Surfaces"
The theory of Widom and Larsen presented in the above manuscripts offers an explanation of the phenomena observed in chemical electrolytic cells employing metallic hydride electrodes (and formerly attributed to "cold fusion").
Experiments conducted in many laboratories using electrolytic cells with metallic hydride electrodes have confirmed the detection of both excess heats of reaction and anomalous low energy nuclear transmutations. Rather than attributing these effects to reactions involving nuclear fusion, the Widom-Larsen theory attributes these phenomenon to weak interactions in which an electron in an EM field combines with a proton to produce a low energy neutron and a neutrino, and the subsequent absorption of the neutron by a nucleus.
The proposed weak interaction process is impeded by (1) the small mass of the electron and proton compared to that of the neutron and (2) the low interaction rate characteristic of weak interactions.
The authors demonstrate that the first obstacle is surmounted under the condition that the mass of the electron is dressed by strong electromagnetic fields derived from surface plasmon modes on the metallic hydride electrodes. The argument in support of this explanation is given (elegantly) in Ref. 1 and in more detail in Ref. 2.
The authors address the second obstacle to the proposed process in Ref. 4, where they conclude that the weak interaction production rate for neutrons is sufficiently large to be consistent with experimental observations. The conclusion is based on both a rough estimate of the production rate, primarily derived from the values of coupling constants, and a more detailed derivation heavily dependent on the formalism of quantum field theory (the latter of which this reviewer, despite a background in field theory, is unable to either verify or disprove).
In addition to providing an explanation for the excess heats of reaction and low energy nuclear transmutations observed in catalysis experiments using metallic hydride electrodes, the Widom-Larsen theory appears to lead to the following testable predictions:
(1) Enhancement of the observed anomalous effects in the presence of laser light incident on the metallic hydride surfaces.
(2) The absence of high energy neutron emission.
(3) The production of copious soft photons.
(4) The non-necessity of deuterium for production of the characteristic effects observed.
(5) The enhancement of nuclear transmutations under the condition of nearly pure proton or nearly pure deuterium systems that better support coherent collective oscillations.
In connection with point (4), Widom and Larsen point out that, whereas electron capture by a deuteron produces an extra neutron, it also requires a renormalized electron mass higher than that needed for electron capture by a proton.
A potential weakness of the Widom-Larsen theory is its reliance on estimates of certain physical quantities. Specifically, the correctness of the author's determination of the renormalized mass of the electron appears to rely on estimates of both the amplitude and the frequency scale of the electric field
oscillations given in Ref. 1; similarly, the determination of the neutron mean free path appears to rely on an estimate of the neutron forward scattering amplitude.
In addition, the theory provides no clear explanation for the excitation of the surface waves resulting in the enhanced electric fields needed to renormalize the electron's mass. In particular, whereas the introduction in Ref. 1 provides an elegant derivation of the dressed mass of the electron produced by a fluctuating electromagnetic field, the point of the initial part of the following discussion on "proton oscillations" eludes me.
The implication is that neutron scattering on protons excites the surface proton oscillations at frequency omega, producing the time-varying electric field that renormalizes the electron's mass.
Instead, the theory appears to require the existence of strong EM field oscillations before the neutrons can be produced.
The theory of the authors, and that based on cold fusion, predicts the production of hard gamma photons not seen in experiments. In Ref. 2, the authors provide an explanation for the nonobservance of hard photons produced by neutron absorption in nuclei on the basis of classical and quantum mechanical derivations of an ultra-short mean free path for hard photon absorption by dressed electrons and their re-emission as multiple soft photons. Included in the same Ref. 2 is a demonstration of the well-known impossibility of absorption of a photon by a free electron (which the authors overkill on page 4 of Ref. 2).
Ref. 3 presents the only direct comparison with data. Here, the authors use a simple optical model potential for the nucleus to estimate the cross section for nuclear absorption of a neutron. This simple model produces a graph of absorption probability versus nuclear mass number A in reasonable agreement with the data.
Experiments find transmuted nuclei with mass numbers as high as 200 in electrolytic cells with electrodes consisting of nickel atoms with an A number only around 60. This experimental evidence for transmuted nuclei with high A, combined with the authors' plausible demonstration that the transmutation processes in electrolytic chemical cells can be produced by low
energy neutrons, suggests that the most significant aspect of the experiments in chemical electrolytic cells may be an alteration in the theory for the production of elements.
Finally, despite the reservations expressed above, I conclude that the mechanism proposed in the Widom-Larsen papers provides a far more compelling explanation of the anomalous phenomenon observed in electrolytic chemical cells than previous theories. Unfortunately, this implies that electrolytic cells using metal hydride electrodes are unlikely to provide a practical source of energy.
Given that the Widom-Larsen theory is correct, the energy you can expect to generate in the electrolysis cell is much less than it would be if the process involved in the cell was the fusion of deuterium nuclei. This is because in the Widom-Larsen process, the production of neutrons via the merger of an electron and a proton actually requires input energy; whereas the capture of neutrons by nuclei produces some energy in the form of hard gamma photons and beta particles (which gets turned into heat), therefore, it's not comparable to that produced in fusion.
More likely, careful measurements of the production rates of nuclear transmutations observed in experiments based on these cells can alter the theory for the production of the elements in the universe.