[Vo]:Enormous current densities in nanowires
Ref[1] points out that certain nanowires can carry enormous current densities (~ 10^11[A/cm^2]) which vaporize macro-sized wires. In metals, this equates to ballistic electron speeds of ~ 100 km/sec - approximately the same as (0-Amp) random thermal electron velocity - far greater than a diffusive electron current drift velocity ~ 1 mm/sec - far less than relativistic speeds. When the wire diameter approaches 1 nm, nearly ballistic electon speeds are possible over lengths of several microns. In some nanowire and e-m field distributions, electrons attain inductive (not kinetic!) energies 1 MeV. Collisions with protons or nuclei can overcome the potential barrier (0.78 MeV) allowing neutron formation. Unless large (AC or DC) current flows are induced, conduction electrons will not acquire significant inductive energy - i.e., they will not acquire large effective mass - a term commonly misunderstood as relativistic mass. Here effective mass is a not a scalar, but a vector quantity measuring electron coupling to the inductive energy of the total current. It is large in direction of large current flow, while small normal to it. This my attempt at a semi-classical check on Widom-Larsen theory. It looks quite reasonable to me, but I could be mistaken. I would appreciate corrections or criticisms. Thanks, Lou Pagnucco [1] Stability of Metal Nanowires at Ultrahigh Current Densities http://arxiv.org/abs/cond-mat/0411058
Re: [Vo]:Enormous current densities in nanowires
On Jan 9, 2012, at 1:39 PM, pagnu...@htdconnect.com wrote: Ref[1] points out that certain nanowires can carry enormous current densities (~ 10^11[A/cm^2]) which vaporize macro-sized wires. In metals, this equates to ballistic electron speeds of ~ 100 km/sec - approximately the same as (0-Amp) random thermal electron velocity - far greater than a diffusive electron current drift velocity ~ 1 mm/sec - far less than relativistic speeds. When the wire diameter approaches 1 nm, nearly ballistic electon speeds are possible over lengths of several microns. In some nanowire and e-m field distributions, electrons attain inductive (not kinetic!) energies 1 MeV. Collisions with protons or nuclei can overcome the potential barrier (0.78 MeV) allowing neutron formation. Unless large (AC or DC) current flows are induced, conduction electrons will not acquire significant inductive energy - i.e., they will not acquire large effective mass - a term commonly misunderstood as relativistic mass. Here effective mass is a not a scalar, but a vector quantity measuring electron coupling to the inductive energy of the total current. It is large in direction of large current flow, while small normal to it. This my attempt at a semi-classical check on Widom-Larsen theory. It looks quite reasonable to me, but I could be mistaken. I would appreciate corrections or criticisms. Thanks, Lou Pagnucco [1] Stability of Metal Nanowires at Ultrahigh Current Densities http://arxiv.org/abs/cond-mat/0411058 You should keep in mind that in nanowires, even (laser induced) thermal pulses move at 2x10^6 m/s, the conduction band electron speed. I am sorry that I do not have the appropriate time to give to this right now. This looks like a very worthwhile and interesting discussion. I do have some differences of opinion with WL theory, as noted on pages 9 and 15 of this article: http://www.mtaonline.net/~hheffner/NiProtonRiddle.pdf Following are some comments on the validity of WL theory: http://www.mail-archive.com/vortex-l@eskimo.com/msg38261.html and the Larsen Widom Patent: http://www.mail-archive.com/vortex-l@eskimo.com/msg42900.html Too bad I have misspelled Widom as Windom consistently for a long time! The WL theory strikes me as out of touch with reality, i.e. with the likelyhood of things like neutron activation. I have heard they might be coming around to a theory more like mine, i.e. where neutrons do not actually form pre-fusion. I haven't read anything of theirs like that though. The following article might also be of interest. www.lenr-canr.org/acrobat/Alexandrovheavyelect.pdf Best regards, Horace Heffner http://www.mtaonline.net/~hheffner/
Re: [Vo]:Enormous current densities in nanowires
Horace, thanks for the reply. You wrote: You should keep in mind that in nanowires, even (laser induced) thermal pulses move at 2x10^6 m/s, the conduction band electron speed. Yes. There are electron-lattice mechanical couplings (e.g,, pinches, phonons, ...) that complicate a simple, classical model, but including them would make the math extremely impossible. I am not at all sure how long a nanowire (or other nano structure) must remain stable, since any nuclear events would disrupt it anyway. However, the paper I cited shows there are some stable operating points (magic conductance values) that can support ultra-high current densities with minimal deformation. I am sorry that I do not have the appropriate time to give to this right now. This looks like a very worthwhile and interesting discussion. No problem. I think that modeling the W-L theory with undergrad physics is the place to start - even if overly simplistic, it may provide insights. It is not too difficult to contrive simple arrays of nanowires with inductive couplings that have already been analyzed in physics textbook chapters on RLC circuit theory. I do have some differences of opinion with WL theory, as noted on pages 9 and 15 of this article: http://www.mtaonline.net/~hheffner/NiProtonRiddle.pdf You may be correct. You are considering at a much finer grain analysis of the reactions. However, it will be much more difficult (I think) to model it. Following are some comments on the validity of WL theory: http://www.mail-archive.com/vortex-l@eskimo.com/msg38261.html Lots of good questions, but my example is not ambitious enough to answer them. I just wanted to see whether classical electrons could surmount a 780 KeV barrier. As far as missing gammas and neutrons, all I can suggest is that the magnetic field encircling the ultra-high current nanowire is gigantic - I am not able to do a QED analysis. and the Larsen Widom Patent: http://www.mail-archive.com/vortex-l@eskimo.com/msg42900.html Perhaps the experimental data is assumed to be the anomalously low gamma emissions in purported LENR reactions. I am not sure.
Re: [Vo]:Enormous current densities in nanowires
On Jan 9, 2012, at 8:11 PM, pagnu...@htdconnect.com wrote: Following are some comments on the validity of WL theory: http://www.mail-archive.com/vortex-l@eskimo.com/msg38261.html Lots of good questions, but my example is not ambitious enough to answer them. I just wanted to see whether classical electrons could surmount a 780 KeV barrier. As far as missing gammas and neutrons, all I can suggest is that the magnetic field encircling the ultra-high current nanowire is gigantic - I am not able to do a QED analysis. You must not have read the post. There are no questions, only assertions. I did not find any question marks. Best regards, Horace Heffner http://www.mtaonline.net/~hheffner/
Re: [Vo]:Enormous current densities in nanowires
Horace, You parse comments way too precisely. I should have said that your observations raise questions. For instance, a key one is - The WL math and QM is possibly controversial (e.g. via Hagelstein and Chaudhary), but the logic and common sense in problem definition and conclusions are clearly controversial and not so complex issues. That seems to imply the question - 'Is W-L theory math correct?' -- unless you are already sure there is no baby in the bath water. I do not know. That's why I looked at the simplest classical analogue I can think of - as a cross-check, an imprecise guide. Also, you statement It would be useful to hear the WL take on why the lack of neutron activation LENR experiments... sure sounds like question unless you mean for the following statements to be interpreted as a definitive rebuttal. Your counterpoints may all turn out to be totally valid. I'm not able to say. To paraphrase the philosopher, Yogi Berra: Theoretically, the theoretical and the empirical are the same. Empirically, they're not. BTW, in slide #25 of Celani's latest presentation - http://www.22passi.it/downloads/WSEC2012%20Present.pdf -- he states: About theory, it is growing the interpretation that such phenomena arise because the Weak Force (Larsen-Widom model) instead the previously thought, usual Strong Force. A well know Researchers (A.Takahashi) recently wrote a model were both forces can be active As for myself, I'm just uncertain. On Jan 9, 2012, at 8:11 PM, pagnu...@htdconnect.com wrote: Following are some comments on the validity of WL theory: http://www.mail-archive.com/vortex-l@eskimo.com/msg38261.html Lots of good questions, but my example is not ambitious enough to answer them. I just wanted to see whether classical electrons could surmount a 780 KeV barrier. As far as missing gammas and neutrons, all I can suggest is that the magnetic field encircling the ultra-high current nanowire is gigantic - I am not able to do a QED analysis. You must not have read the post. There are no questions, only assertions. I did not find any question marks. Best regards, Horace Heffner http://www.mtaonline.net/~hheffner/
