Physics/Disintegration of Lithium
QUESTION: Traubenburg established that a slow proton, a hydrogen ion, at a low voltage at 29kV would disintegrate a lithium nucleus without an actual collision as it traveled by far outside the lithium nucleus. This excursion developed energy. Why cannot we develop that same type of energy in a combustion enviornment, by applying to it 29kV voltage pulses and a lithium vapor in hopes the the violent free radical, molecular and ionic collisions (10 billion /sec) during combustion could propogate the energy realized as when lithium was disintegarted during the early lithium experiments. i.e. Traubenberg or Cockroft and Walton
ANSWER: No, that's not quite right. Proton bombardment of light elements can cause a nuclear fusion reaction by their capture of through a different reaction (what you refer to as disintegration). The probability of such reactions occurring when the hydrogen ions are at very low indeed. You need a large number of such ions with a tremendous amount of total energy to get fusion, this is indeed a goal of fusion reactors. Lithium 7 and boron 11 are favored targets for the far future when enough energy can be packed into enough space (as the disintegration you mention causes the release of helium but only the most minimal production of radioactive material), but in the meantime deuterium and tritium are the favored reactor fuels for NIF and ITER (see their websites for details) because the technology is almost ready to get us to the energy production stage. Almost. Basically, what you're talking about is what people have been working on since the 1960s and before...and we have yet to achieve the goal of energy production. Will it happen? Yes. Is it as simple as your question makes it seem? Absolutely not, but you're thinking in the right direction for sure.
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QUESTION: Hi Steve, Appreciate the feedback but I am not quite sure what you hink is not quite right. My description of the Traubenberg experiment which seems to be established science and underscored by Max Born in his book Atomic Physics or my use of the term "disintegration of lithium" which was used by The Physical Review in 1936. I understand that there is a tunelling mechanism which I think you are referring to but that is different from the Traubenberg experiment. So my question was if the binding energies of a lithium nucleas can be overcome with near collisions in a 2 demensional enviornment (Traubenberg), why cannot we see if we can to the same in a 3 demensional combustion and reap the obvious benefits of added extar energy and less products of hydrocarbon combustion?
ANSWER: No, you're talking about well-studied experiments and you're also talking about exactly what my graduate dissertation was about and my group focused on. I've had years of experience doing what you asked about in the lab, I know what I'm talking about. These have been going on since Cockroft and Walton in 1933, of course the science is established. What you're discussing is the 7Li(p,alpha)4He reaction. The p is for proton, the alpha is for the emitted alpha particle, and the first and last isotopes are the target and residual nuclei, respectively. This reaction does indeed releases 17.35 MeV of energy, yes! But for the particles you accelerate to your aforementioned experiment, only the tiniest fraction of them will actually undergo this reaction. The vast, *vast* majority will simply stop in the lithium through ionization and collisions with the lithium target. You'll waste far more energy than you'll ever see out of the nuclear reaction itself, and most of it will be emitted as largely useless (and dangerous) 17.255 MeV gamma rays (and 0.091 MeV of alpha disintegration of the resulting unstable 8Be nucleus). The environment you mention is not two-dimensional at all, it's three dimensional in all these experiments. I'm not sure why you even plugged that in here, but this is not as easy to just up and generate energy out of as you're implying in the slightest. Really, read something about nuclear physics that was not cooked up in the 1930's when they were barely figuring this stuff out or trust the 80 years of knowledge that experts have accumulated since before you take an ancient experiment and try to produce energy. If it worked that way in the slightest, we wouldn't be mining coal almost at all by now, and not just because "no one thought of it yet." Scientists think about applications of this nature all the time, good ones.
Oh yeah, see here: http://www.tunl.duke.edu/nucldata/figures/08figs/08_04_2004.pdf
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QUESTION: Thanks Dr. Nelson. Appreciate your feedback again. So you agree that a tiny amount of disintegration happens to the lithium nucleas without actual collisions per the Traubenberg experiment. And as you say it is a very inefficient way to generate energy based on the specific configurations of those experiments. What I meant by my 2 demensional reference was that sure technically the experimental platforms were 3 demensional but what I meant was to bring the experiment into a volumetric enviornment , a furnace, and take advantage of the 10 billion collisions per second of atoms, ions, molecules etc in that violent turbulent enviornment and see if we could take advantage of that highly energetic space and try to spawn that tiny amount lithium reaction. If we could get the tiny amount to react, would not that cause a propogation effect as the aphas collide with neighboring hydrocarbon chains as well as other lithiums that we saturate in the furnace space? Seems this would change combustion for the better. Ha anyone tried this? I did not mean to say you did not know what you are talking about. Just wanted to make sure you understood me as a lay person. In a past life I set up combustion furnaces for a large boiler manufacturer and I always wondered about this potential. It is truley a priviledge that I can have a discussion like this with a person of your stature. Thanks Joe D
No, I do not agree that it happens "without collisions." That's not what the experiment you referred to actually concluded, the products in the original experiments were shown to be helium. That means the proton was incorporated in the nucleus. Quantum tunneling was a new idea back then, so if you didn't see it specifically referenced in one of a dozen papers then I'm not surprised, but I went and looked up the particulars of the experiments and trust me...it's standard hot fusion. Combustion heat is far too low to be of any use in such a reaction, the two types (nuclear and chemical) are on completely incompatible energy scales. Fusion plasmas require types of confinement that precludes their touching containers which can contain normal chemical combustion. The typical energy in high-temperature combustion is only about 0.1 eV, and the dependence on energy for tunneling through the Coulomb barrier is exponential.
Prime example: The Sun. If nuclear reactions didn't happen very slowly at even millions of Kelvin, then the Sun and stars like it wouldn't last for billions of years...they'd just blow up. And they're far more dense and hot than any typical combustion reaction. Leave fusion power to the people working on projects like ITER and NIF, they're racing to get there first.