Historical research guide · 0480 · 1989

“Nattoh” Model for Cold Fusion

Takaaki Matsumoto

In one minute

Within months of the Fleischmann and Pons announcement, Takaaki Matsumoto of Hokkaido University’s nuclear engineering department published a three-page attempt at a mechanism. Cold fusion experiments were reporting heat, neutrons and reaction products that ordinary two-body deuterium fusion could not tie together, and Matsumoto asked what arrangement of matter inside a metal could. His answer is the Nattoh model, named for the fermented soybean dish whose sticky strands the structure resembles: hydrogen or deuterium atoms trapped in the tiny cavities of a metal — grain boundaries, defects, interfaces — pack into a small cluster and, past a critical pressure under current flow, compress themselves. Inside such a cluster, nuclei are no longer meeting two at a time, and Matsumoto works out the feasibility of many-body fusion reactions among them. He then does the thing that makes a model testable: he says what you should see. Gamma-ray spectrum, heat production, neutron emission and fusion products are each discussed against the reported measurements.

Connection

Chapter 12 is built on the idea that the barrier between two nuclei is set by their environment rather than being a fixed wall, and this is one of the earliest attempts to name the environment precisely — a self-compressed cluster in a lattice cavity. Chapter 9 takes the same object from the other side, because a dense, self-organised cluster of charge and nuclei is exactly the sort of thing the exotic-vacuum-object literature has been describing ever since.

From the source

A hypothetical model, the Nattoh model, is proposed to answer the questions that result from cold fusion experiments — that is, it is offered as a mechanism for observations already reported rather than as a prediction made in advance.Author abstract, opening sentence; Fusion Technology 16, 532 (1989)
The model proposes the formation of a small cluster of deuterons, and examines the feasibility of many-body fusion reactions within it — reactions among more than two nuclei at once, which is what allows it to reach for products that two-body deuteron-deuteron fusion does not give.Author abstract, second sentence
The model rests on a single hypothesis, in the author’s own later words: hydrogen clusters consisting of more than two hydrogen atoms, trapped in tiny cavities such as grain boundaries, defects and interfaces in a metal, compress themselves to induce hydrogen-catalysed fusion reactions when the hydrogen pressure exceeds some critical value under electrical current flow.Restated by Matsumoto in Fusion Technology 24, 296 (1993), Introduction, citing the 1989 paper as reference 3
Because the mechanism turns on cluster self-compression rather than on anything specific to deuterium, the model predicts that cold fusion can take place by the same mechanisms with ordinary water as with heavy water — a prediction made in 1989, before the light-water experiments that later tested it.Fusion Technology 24, 296 (1993), Introduction, first paragraph, citing the 1989 model
The paper names its own observable signatures rather than leaving the model unfalsifiable: the gamma-ray spectrum, heat production, neutron emissions and fusion products are each discussed.Author abstract, closing sentence
What would settle it is direct evidence of the compressed cluster itself, since that single object is the model’s only assumption; Matsumoto’s own route was to go looking for the predicted signatures in nickel foil and ordinary water, published in Fusion Technology in 1990 and again in 1993.Site framing; the follow-up experiments are Fusion Technology 17, 490 (1990) and 24, 296 (1993)

The way in

https://doi.org/10.13182/fst89-a29119

Historical source-access record. This guide links to the original; it does not reproduce the paper text.

WHAT THIS IS. A three-page theory note in Fusion Technology, volume 16, issue 4, pages 532 to 534, December 1989 — written in the first months after Fleischmann and Pons, by a nuclear engineer at Hokkaido University. LICENCE. Crossref records no licence at all for the article, and OpenAlex and Unpaywall both report it closed with no repository copy, so no text is reproduced here. WHAT WAS READ IN ITS PLACE. Two things. First, the author’s own abstract, which is public in the OpenAlex record for the article and is the source of the claims about the model’s content. Second, and more usefully, Matsumoto’s own restatement of the model in his later paper ‘Cold Fusion Experiments with Ordinary Water and Thin Nickel Foil’, Fusion Technology volume 24, pages 296 to 303, November 1993, which is free to read at lenr-canr.org/acrobat/MatsumotoTcoldfusionb.pdf and was downloaded and read in full for this sheet; it cites the 1989 paper as its reference 3 and states the model’s single hypothesis in the author’s own words. Locators name whichever of the two carries the sentence. WHAT IS NOT CARRIED HERE. The 1993 paper also reports nuclear-emulsion traces that Matsumoto interprets in far more exotic terms. Those interpretations belong to the 1993 paper and are not part of the 1989 model, so they are not summarised as claims of this work. THE NAME. Nattoh is nattō, the fermented soybean dish, whose sticky strands the chained cluster is named for; Matsumoto carried the metaphor into his own terminology in the later papers. LENR-CANR.org, Jed Rothwell’s library, holds three Matsumoto papers but not this one.

How to cite it

Takaaki Matsumoto (1989) “Nattoh” Model for Cold Fusion doi:10.13182/fst89-a29119

Where it sits in the curriculum

Lattice confinement fusion