I got mixed signals from Dr. Bussard on the matter. Almost as soon as he hired me, he showed me a reprint of the following paper, which concludes there are fusion reactions possible, they can produce net heat, and they would probably be more practical with nickel electrodes. He believed the reactions would not be direct DD, but would be "virtual", occuring by some process mediated by the nuclei of the electrode metal (apparently related to muon catalysis pathways). High fuel density in the electrodes, near infinite confinement times, and naturally very short range for Coulomb repulsion set the stage ... quantum mechanics within the lattice makes it possible. I have some trouble following the more advanced parts.
"Virtual-State Internal Nuclear Fusion in Metal Lattices"
Robert W. Bussard
Fusion Technology, v. 16, p 231
Sept 1989
Note this is George Miley's fusion journal, for ANS.
Dr. Bussard was, nevertheless, a sharp critic of most CF claims, and P & F particularly. He gave me a copy of John Huizenga's Cold Fusion: The scientific fiasco of the century to emphasize the point.
Note to Warthog: Jeff actually doesn't justify his claims in that article. In his discussion on the Analog board, he says the reason he did not present a proof and supporting citations is simply that he intended the article as a book report. Here's part of his comment (he won't mind the quote):
"Dave B. www.lenr-canr.org Thousands of refs, some of them you might even like."
(paragraph skipped)
"The bulk of the column was a book review. The author runs a site www.newenergytimes.com. I do not look fondly upon people who ask me to do things for them that they could do for themselves in less time than it takes to ask me. You have Google. You have the Internet. Go for it."
Cold Fusion
Re: Cold fusion real?
[quote]" What resulting products? Helium/Alphas? Are my Ionizing smoke detectors then doing Fusion too? How do you conclude Alphas mean Fusion?"[/quote[
An alpha particle (He4) would be the result of an aneutronic fusion of deuterium. Your smoke detector is generating alpha's as a result of nuclear decay of a very heavy radioisotope (usually Americium)--not fusion. The fact that the alphas are traveling at very high velocities (as they must to traverse the solution gap between the palladium foil and the track-etch coupon) indicates fusion. There is no radioisotope present in the palladium to produce a high-energy alpha UNLESS there has been a fusion reaction.
An alpha particle (He4) would be the result of an aneutronic fusion of deuterium. Your smoke detector is generating alpha's as a result of nuclear decay of a very heavy radioisotope (usually Americium)--not fusion. The fact that the alphas are traveling at very high velocities (as they must to traverse the solution gap between the palladium foil and the track-etch coupon) indicates fusion. There is no radioisotope present in the palladium to produce a high-energy alpha UNLESS there has been a fusion reaction.
Actually, the paper I cite above calculates reaction pathways for the two main DD fusion pathways we think of in plasma (normally nearly equal in probability), and concludes the path leading to tritium and a proton is about 5500 times as likely as the He3, n pathway in the metal lattice situation. He said nothing about He4 regarding DD fusion.
I have not been following the field and don't know what the experiments have been turning up. I do recall at least one paper (I don't have a reference, but it may have been in Fusion Technology in the 1990's) which found wholesale transmutation of electrode metal, which Bussard predicted. In this case, thinking in terms of DD fusion is a red herring.
Helium is a "magic number" nucleus (multiples of 2 protons, 2 neutrons) and is a common end-point of many nuclear disintegrations, hence alpha radiation is common in radioactive decay.
I have not been following the field and don't know what the experiments have been turning up. I do recall at least one paper (I don't have a reference, but it may have been in Fusion Technology in the 1990's) which found wholesale transmutation of electrode metal, which Bussard predicted. In this case, thinking in terms of DD fusion is a red herring.
Helium is a "magic number" nucleus (multiples of 2 protons, 2 neutrons) and is a common end-point of many nuclear disintegrations, hence alpha radiation is common in radioactive decay.
Yes, but that's "in plasma". The situation in "condensed matter fusion" seems to be different. The track etch experiments directly measure high energy particles impacting a plastic coupon. There is no way that alpha particles of such energies can be generated with the small appied voltage in "cold fusion" cells without "some" nuclear process taking place. Detecting neutrons is difficult, especially when they are present in very low numbers, and much criticism has been directed at CF researchers because there are so few neutrons.. I don't know of any mechanism that will "fool" a track-etch dosimeter.Tom Ligon wrote:Actually, the paper I cite above calculates reaction pathways for the two main DD fusion pathways we think of in plasma (normally nearly equal in probability), and concludes the path leading to tritium and a proton is about 5500 times as likely as the He3, n pathway in the metal lattice situation. He said nothing about He4 regarding DD fusion.
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Art Carlson
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Try http://pages.csam.montclair.edu/~kowals ... p08217.pdf and http://www.lenr-canr.org/acrobat/Kowals ... earorn.pdfWarthog wrote:I don't know of any mechanism that will "fool" a track-etch dosimeter.
Warthog,
In plasma? No, Dr. Bussard's paper was specifically for the case in metal lattices, and Gamow barrier physics were important to the pathway. Look it up on Wikipedia and you will have all I know about Gamow barriers ... in this case it is a quantum pathway for getting past the Coulomb barrier.
To quote (trimmed down a trice and without the proper typography) the citation above:
The usual formulas for fusion interaction cross sections (ref 8 ) show that the Gamow barrier penetration probability is proportional to (formula skipped for awkward typography) at energies E < 50 keV, where a sub i are constants determined by the interaction potential functional shape. Taking standard values for these, for the two main branches of the D-D reaction, gives the branching ratio betwen the (He3, n) and (T, p) as
sigma (He,n) /Sigma (T,p) = 1.352 exp(-0.897/ sqrt(E)) = Rn.
For E = Eq in keV, for D-D virtual pairs in the center of mass frame. From this it is readily seen that the (He3, n) branch will be frozen out at normal (small) lattice energies. For example, if the lattice DD pairs are bound (virtual state) at an equivalent energy of Eq = 10 eV .... the (T, p) branch is > 5500 times more likely than the (He3, n) branch.
End quote.
One notes this is a ratio of probability of reaction, both of which could be approximately zero at 10 eV, for all I know. Whatever is in ref 8 is obviously pretty important, especially the constants in that deleted equation.
Anyway, it was interesting to see Art post something that challenges the detection method but which otherwise seems to support LENR. I'd be much more interested in well-controlled demonstration of wholesale nuclear transmutations and isotope abundance shifts, which seem to occur in the better experiments.
In plasma? No, Dr. Bussard's paper was specifically for the case in metal lattices, and Gamow barrier physics were important to the pathway. Look it up on Wikipedia and you will have all I know about Gamow barriers ... in this case it is a quantum pathway for getting past the Coulomb barrier.
To quote (trimmed down a trice and without the proper typography) the citation above:
The usual formulas for fusion interaction cross sections (ref 8 ) show that the Gamow barrier penetration probability is proportional to (formula skipped for awkward typography) at energies E < 50 keV, where a sub i are constants determined by the interaction potential functional shape. Taking standard values for these, for the two main branches of the D-D reaction, gives the branching ratio betwen the (He3, n) and (T, p) as
sigma (He,n) /Sigma (T,p) = 1.352 exp(-0.897/ sqrt(E)) = Rn.
For E = Eq in keV, for D-D virtual pairs in the center of mass frame. From this it is readily seen that the (He3, n) branch will be frozen out at normal (small) lattice energies. For example, if the lattice DD pairs are bound (virtual state) at an equivalent energy of Eq = 10 eV .... the (T, p) branch is > 5500 times more likely than the (He3, n) branch.
End quote.
One notes this is a ratio of probability of reaction, both of which could be approximately zero at 10 eV, for all I know. Whatever is in ref 8 is obviously pretty important, especially the constants in that deleted equation.
Anyway, it was interesting to see Art post something that challenges the detection method but which otherwise seems to support LENR. I'd be much more interested in well-controlled demonstration of wholesale nuclear transmutations and isotope abundance shifts, which seem to occur in the better experiments.
Last edited by Tom Ligon on Sat Feb 07, 2009 2:21 am, edited 1 time in total.
Ref 8 above, if anyone wishes to look up the Gamow barrier pathway (I've not seen it and I'm frankly not that ambitious regarding LENR)
G. H. Miley, H. Towner, and N Ivitch, "Fusion Cross-Sections and Reactivities," COO-2218-17, University of Illinois (1974).
I find this also as ref 28 in the 2007 NRL Plasma Formulary, so it would seem to be a mainstream accepted source. This reference is used to show the calculation of fusion cross-sections (p. 44), with a table of the a constants given as the Duane coefficients. I was unable to find the original reference on-line, but the NRL Plasma Formulary is readily available.
Do note this publication pre-dates all the CF furor. The Gamow barrier, from what I read today, is a known and accepted QM shortcut around the Coulomb barrier, although usually used to explain modestly higher reaction rates than would be explained by the Coulomb barrier alone in conventional fusion reactions. I have no idea how good the calculations are at very low energies, but if CF is real, this topic should be important.
G. H. Miley, H. Towner, and N Ivitch, "Fusion Cross-Sections and Reactivities," COO-2218-17, University of Illinois (1974).
I find this also as ref 28 in the 2007 NRL Plasma Formulary, so it would seem to be a mainstream accepted source. This reference is used to show the calculation of fusion cross-sections (p. 44), with a table of the a constants given as the Duane coefficients. I was unable to find the original reference on-line, but the NRL Plasma Formulary is readily available.
Do note this publication pre-dates all the CF furor. The Gamow barrier, from what I read today, is a known and accepted QM shortcut around the Coulomb barrier, although usually used to explain modestly higher reaction rates than would be explained by the Coulomb barrier alone in conventional fusion reactions. I have no idea how good the calculations are at very low energies, but if CF is real, this topic should be important.