By Steven B. Krivit

The debate about Low-Energy Nuclear Reactions does not have two sides. It has three; they represent three distinct paradigms.

Bringing Back LENRs
The term LENR is not new. It was first used in 1995 when some scientists in the field, specifically John Bockris and George Miley, recognized that the experimental results they were seeing could not be caused by fusion, but had to be the result of some other kind of nuclear reaction. Those scientists and their research were marginalized by other scientists in the field who were ideologically aligned with the "cold fusion" idea. The term LENR did not take root at that time, however, when the Department of Energy facilitated another review of the field in 2004, the DOE primarily identified the research as LENRs.

Beginning in 2008, as a result of what I had learned about the experimental results, I shifted all my communications — the New Energy Times Web site, my journal papers, encyclopedia chapters and conference presentations — to identify the research as LENRs rather than "cold fusion." I encouraged others to so as well. By 2010, after I had distinguished between LENRs and "cold fusion," and written extensively about the Widom-Larsen theory, some LENR scientists said that a neutron capture process could be considered a new form of nuclear fusion. Thus, they attempted to redefine the meaning of fusion. I discussed this in the article "Neutron Capture Is Not the New Cold Fusion." By around 2020, the term LENR, or LENRs, was broadly, but not fully adopted.

Paradigm 1 — LENRs Are Not Possible
The first paradigm holds that nuclear reactions initiated by low-energy stimuli (below 1 keV) are not possible. This is the dominant paradigm, and it has been for more than 100 years.

Paradigm 2 — LENRs Are Possible, Based on "Cold Fusion"
The second paradigm holds that nuclear reactions initiated by low-energy stimuli (below 1 keV) are possible and the underlying mechanism is based on the hypothesis of room-temperature fusion, also known as "cold fusion." This is not to be confused with muon-catalyzed fusion, discovered by Luis Alvarez and colleagues in 1956. That research is not contested; it's consistent with known physics, and it has never demonstrated any experimental evidence as a possible energy source.

The hypothesis of room-temperature fusion was suggested by electrochemists Martin Fleischmann and Stanley Pons in 1989. Their announcement inspired thousands of scientists around the world to attempt to repeat their experiment. Most failed. A few hundred saw some experimental results, although they were not consistent with the products expected based on the theoretical understanding of deuterium-deuterium fusion. These scientists saw the results with their own eyes and instruments they trusted. Most of the experimentalists who continued with the research focused their attention empirically, giving little regard to theory. Alternatively, most theorists in the field pursued explanations based on fusion.

A simplified equation that depicts the putative room-temperature fusion reaction is D+D → 4He + 24 MeV, meaning that two deuterium nuclei undergo a fusion process and form one helium-4 nucleus.

It assumes that, for every fusion reaction in a LENR experimental system, 24 MeV of energy is released and that all of that energy is associated with the production of one helium-4 atom. This was a key part of the claims made by electrochemist Michael McKubre. Although McKubre had indeed found evidence for excess heat and helium-4 production, I discovered that McKubre had made a series of changes to the data to give it the appearance of supporting the "cold fusion" idea.

The "cold fusion" idea asserts that all other reaction products — for example, tritium, isotopic shifts, transmutations, and alpha particles — observed in LENR systems are produced without significant energy release. It also asserts that no other reactants — for example, normal hydrogen — produce positive results in LENR systems. These assertions were a central part of a peer-reviewed journal paper published by "cold fusion" scientist Edmund Storms. As his assertions were inconsistent with the facts as I knew them, I submitted and published a peer-reviewed response providing evidence that refuted Storms' assertions.

Paradigm 3 — LENRs Are Possible, Based on Neutron Reactions
The third paradigm holds that nuclear reactions initiated by low-energy stimuli (below 1 keV) are possible and the underlying mechanisms are based on neutron reactions.

A simplified equation, specifically applicable to the Widom-Larsen proposed theory, depicts the putative neutron-based reaction as e_n + p_n → n + v. This means that a number of electrons and a number of protons undergo a neutronization reaction which forms an ultra-low-momentum neutron and a neutrino. This reaction requires energy input and is distinct from an inverse beta decay.

Once a source of neutrons exists in a LENR system, a variety of subsequent nucleosynthetic reaction processes and decays can explain the production of helium-4, tritium, isotopic shifts, transmutations, and alpha particles, as observed in LENR systems. Neutron-based theories can explain LENR systems that use deuterium or normal hydrogen as reactants. They can explain upward and downard changes in atomic number.

Evolution of Ideas
In 1951, a young Cornell University graduate named Ernest Sternglass boldly speculated about making neutrons from a relatively low-energy experimental system. He tested his hypothesis, and it worked. Nobody at Cornell believed him so he courageously wrote to Einstein. Rather than dismiss Sternglass as a crank, Einstein had an open mind and even speculated that collective effects might produce the necessary input energy to create neutrons.

In October 1989, Edward Teller, a famous Manhattan Project nuclear physicist, was one of the people who suggested a neutron-based explanation. After he assessed the results of experiments performed at the Lawrence Livermore National Laboratory and similar results obtained at the Naval Research Laboratory, he thought that these experiments showed evidence of real nuclear reactions. (Read more about this in my book Fusion Fiasco.) But fusion seemed improbable to him. Instead, he thought that something like a neutron might be responsible for the reactions.

"Perhaps a neutral particle of small mass and marginal stability is catalyzing the reaction. You will have not modified any strong nuclear reactions, but you may have opened up an interesting new field," Teller said.

In the next 16 years, other scientists who followed LENR research also suggested that the reactions were caused by neutrons. They included Larry A. Hull, Peter Hagelstein, Tadahiko Mizuno, Yasuhiro Iwamura, Mitchell Swartz, John Fisher, George Anderman, Hideo Kozima, Lali Chatterjee, and Stanislaw Szpak.

The presence of neutrons in LENR systems easily explains the variety of experimental results reported. But where would those neutrons come from? No one had published an explanation until, in 2006, Allan Widom and Lewis Larsen published the Widom-Larsen Ultra-Low-Momentum Neutron-Catalyzed Theory of Low-Energy Nuclear Reactions. I tell their story in my book Hacking the Atom.