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Re: [Phys-l] Watch "60 minutes" today



On Apr 20, 2009, at 7:10 PM, John Clement wrote:

I did not get to watch the 60 minutes presentation, but I did look at the
web site. I was not impressed by the web site. In one video they
disclaimed that there were any nuclear processes, and the investigator
essentially implied he did not have much knowledge of physics.

In the second video they claimed deuterium fusion. If this really happens
then there should be an independent way of verifying this. The explanation
of why there is fusion sounded like gobbledy-gook to me. Now if someone
else can explain his explanation in more reasonable terms, I would be glad
to read it.

They claim to be designing this effect for home heating!!! I am not sure I
want a fusion reactor in my home.


1) Let me begin with what is well known about fusion of two deuterium nuclei, for example, by bombarding a deuterium target with a beam of accelerated deuterons. The experimental results are in reasonable agreement with what is predicted theoretically; it is a QM problem of coulomb barrier penetration. The fusion probability is very low at ~10 keV; it becomes nearly three orders of magnitude larger at ~100 keV, etc.

But no matter what the initial energy is, the outcome of such fusion is always the same: about one half of collisions result in 3H+1H (production of tritium and protons, of combined energy of 4 MeV). The other half of collisions result in 3He+1n (production of 3He and neutrons, of combined energy of 3.3 MeV). And rarely (one out of million collisions) the output is 4He + a photon of 18 MeV. All this is well known.

2) One argument against cold fusion was that kinetic energies of deuterium ions, at room temperatures (even far above the most probable energy of 0.04 eV, if I recall this number correctly) are too small to make fusion possible. The other argument was as follows. Suppose that cold fusion of two deuterons is responsible for generation of measured excess heat at the rate of about 1 W. How many neutrons would be produced? The energy of each neutron is known to be close to 2.5 MeV (a fraction of 3.3 MeV released by the corresponding fusion reaction). Neutrons are produced in one half of collisions. Thus they contribute a little less that 0.5 W=0.5 J/s or about 3*10^12 MeV/s. The estimated answer is 3*10^12/ 2.5=1.2*10^12 neutrons per second. Attempts to detect neutrons, emitted from electrolytic cells, were made but they were not successful. Attempts to detect photons of 18 MeV were also unsuccessful.

3) I cannot speak for Mike McKubre. But I can imagine what he would say to John C. First he would probably show a beautiful experimental result--a correlation between the amount of excess heat and the number of helium atoms produced in the cathode of his cell. Mike was one of several people who independently demonstrated such a correlation. His result was a straight line (with large random errors but many data points). The slope of the line was one atom of helium per 23 MeV of excess heat. That is what one would expect by comparing the mass of two deuterium atoms with the smaller mass of one helium atom.

Mike would take it for granted that production of neutrons and tritium, if any, certainly does not match the rates corresponding to the amount of excess heat. Therefore, he would say, "it must be a new nuclear process." The mechanism of this process (taking place inside the palladium lattice) is not known. But production of helium from deuterium, he would emphasize, is a nuclear process, even if it is not a simple two-body collision. The released energy, he would speculate, goes directly into the lattice (as in Mosbauer effect). That is why no radioactive byproducts are produced.

4) None of this conflicts with the idea that some neutrons and tritons, or photons, are occasionally produced. But the amounts are negligible in comparison with what is produced in a nuclear reactor. Unfortunately, the term cold fusion is still used (for sentimental reasons, I suppose). Most researchers now use the term CMNS (Condensed Matter Nuclear Science) or LENR (Low Energy Nuclear Reaction). It is remarkable that, at the end of the interview, Martin Fleischmann mentioned two things he regrets: using the term cold fusion and agreeing on the press conference. I remember him saying, four years ago, that they wanted to wait another year (to perform more experiments and to publish a paper). The press conference, he said, was imposed on them by the university administration.

P.S.
Here is a better link, for those who want to see the interview again. The link I posted yesterday was for the entire program (1 hour); the link below, I was told, is for the relevant interview only.

http://www.cbsnews.com/video/watch/?id=4955212n

P.P.S.
Reproducible experiments, demonstrating the reality of a nuclear effect resulting from a chemical effect, would be a great challenge to theoretical physicists. The prevailing view is that nuclear processes (associated with nucleons inside atomic nuclei) are not influenced by chemical processes (associated with atomic electrons). Fortunately, researchers on both sides of the controversy agree on an acceptable methodology of validation. I am still waiting for at least one teacher willing to participate in the Curie Project. For details see:

http://csam.montclair.edu/~kowalski/cf/359anniversary.html

- - - - - - - - - - - - - -
Ludwik Kowalski, a retired physics teacher and an amateur journalist. Updated links to publications and reviews are at:

http://csam.montclair.edu/~kowalski/cf/ http://csam.montclair.edu/~kowalski/my_opeds.html http://csam.montclair.edu/~kowalski/revcom.html

Also an ESSAY ON ECONOMICS at: http://csam.montclair.edu/~kowalski/economy/essay9.html