Quantum world views - It's what make fusion happen

It may be difficult to separate "theory" from "application," but let''s see if this helps facilitate the discussion.
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Richard Hull
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Quantum world views - It's what make fusion happen

Post by Richard Hull » Sat Aug 22, 2020 8:59 pm

Is it important to know and understand Quantum physics to do fusion?...Absolutely not! It is important, however, to have a rudimentary understanding of its principles. We need to understand how "Quantum uncertainty", and in our case, "Quantum tunneling" aids us and yet limits energy producing fusion. These quantized functions have an iron grip on the fusion process in the world of the small.

We all have to accept that fusion, at our level of performance or perhaps at any level, is due to quantum level interactions and uncertainties, which at the core, are 100% probabilistic in a quirky and very spooky way. When all the smoke clears, we are rolling the dice in a quantum world and hoping for a real world result of some benefit, (creating useful energy).

It is painfully obvious that we are not having one round solid ball deuteron impact flawlessly, head-on, with another deuteron at some energy "X" that is well known to create fusion. We know that is not true and will never happen. Even such idealistic head-on collisions in a hail of particles, would turn back into a probability solution, but at least a totally predictable, non-spooky fashion.

The real research at the real world level shows that direct hits, even at full fusion energy, may not result in a fusion. Full fusion energy is usually about where fission, or in our case, D-D "stripping" via the Oppenheimer-Philips reaction occurs. We do fusion at such a low energy level that we are forced to rely totally on "Quantum tunneling". Fusion, for us, is totally probabilistic, but at a rather spooky quantum level which we can't control, but can direct in a real world fashion by creating a super complicated, many body, energetic environment which, due to its quantum nature, does fusion.

Quantum theory, in our case, is not of single, joined or bound system of particles at room temperature where total stability reigns, as in a kernel of corn. We work in a "densified" group of totally unbound, yet somewhat confined, recirculating, energetic single entities of the same charge that do not want to come together! Fusion, be it thermal plasma heating or electrostatically confined fusible fuel, will remain a losing crap shoot with "containment" of the complex single particle, electrostatically repellent assemblage! The weakness of all fusion systems is due to quantum uncertainty or Quantum tunneling, in our case.

Containment of the repelling particles at usable fusion energies and density is the ultimate problem in doing useful fusion. This issue is yet to be solved, as all such grossly imbalanced, energetic systems seek to find their lowest energy state. (cool down or leak away into an unbound state)

Fusion "cross sections" are a symbol of, and the ultimate limiting factor in fusion. These cross sections are all based on observed quantum fusion probabilities at varying energies of two body, "tunneling" collisions among many particles. Fusion can even occur with a non-contact very close pass-by or approach.

Quantum theory is, itself, a usable model, only, and not a fixed edifice as is discussed at some length in this article in Scientific American.

https://www.scientificamerican.com/arti ... ket-newtab

Enjoy straining your brain a bit. Newbies without the chops to follow might find all this a bit confusing. You will see even the mighty are out there thinking. As they learn or believe they have learned, they then tell us what to think in the classroom. Fail at understanding and you will not make the grade. College "pass-men" are just that.... pass-men, like me, who are there to be hired in better jobs than the rest of the herd. The best part of college was to be teaching you to think, question and know how to ferret out data to help you think deeper and better. Once out of college, it is to work and family, buying a home, paying bills and only old farts like me, in retirement, dare try to think deeply again. But alas, it is often too late and a vanity to take to the grave.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.

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Dennis P Brown
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Re: Quantum world views - It's what make fusion happen

Post by Dennis P Brown » Sun Aug 23, 2020 12:08 pm

Excellent overview of the fusor process. Certainly, not a process that has any real analogy in the real world so can be a bit weird for most people to accept.

As for us older folks continuing to think (education), that is also one of the best ways to keep the mind sharp. Your continued and improved experiments in fusor induced activation are both impressive and inspiring; that too keeps one sharp, as well.

Scientific American (and started my subscription, finally, again) is still the best general science magazine for people of a scientific bend who can handle more than the average level.

And with google, little excuse for anyone to not figure out how to cross check and learn rather than accept what their too often believed to be 'betters' on the internet tend to post with no proof. All one has to do is maintain an open mind, and do some simple research (i.e. invest a tiny bit of intellectual effort rather than accept these pronouncements - even if it supports one's world view.) But hey, stay off my lawn ...oops, freudian slip ;) .

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Re: Quantum world views - It's what make fusion happen

Post by Nicolas Krause » Tue Nov 03, 2020 5:41 pm

Can anyone suggest some good resources for learning about fusion and the nucleus? I'm currently reading Models of the Atomic Nucleus by Norman D. Cook, which is a nice overview of the different approaches, liquid drop, shell etc.. I have a good sense of what to search for when I want to learn some math, but with Physics I don't seem to have as much luck.

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Re: Quantum world views - It's what make fusion happen

Post by Dennis P Brown » Wed Nov 04, 2020 2:10 pm

Most "Modern Physics" text books cover the nculeus in a more realistic manner. You can skip the Special Rel. in these books, of course.

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Re: Quantum world views - It's what make fusion happen

Post by Nicolas Krause » Sun Nov 08, 2020 5:33 pm

Thanks Dennis, I'll take a look at a few of those. Does anyone have any experience with lattice models of the nucleus? I know the standard/older models are liquid drop and shell types, but I'm curious if anyone has investigated the idea that there's an ordered structure to the nucleus and its potential impact on fusion.

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Re: Quantum world views - It's what make fusion happen

Post by Richard Hull » Sun Nov 08, 2020 10:33 pm

Nicolas, You are digging in as only our ideal poster might. The question you ask here is one for the ages. When digging this deep into nuclear physics, things get very murky. Science is and has been just guessing on this topic for years. We invented the strong and weak nuclear forces, and many other things upon which we say, "We can't see it but it must be real", concepts over the years. We even have mathematical reductions of precisely what these inter- nuclear forces must be and how they must interact. All of this is part of the standard model. It has ranged far and deep into a black abyss where great guesses are made, with suitable mathematics to bolster the concepts posited. Everything seems to work mathematically. It is a "best fit". It has to fit or we dare not call it science. The quantum limit has not stopped the musing and searching.

Take all you read with a grain of salt regarding a nuclear "nucleus model". We seem to have done it to a working level with the electron shell model, extra-nuclear. The important thing to realize is we will never have what we feel is a reality in the normal sense of a ponderable, physical reality, once you touch the "quantum barrier".

The quantum barrier exists, like it or not, just below the molecular level of solid reality. I was once enthralled with the shell model where the nucleus was envisioned to be a assemblage of helium nuclei. But that was before I realized reality is hazy at that level. It is natural to seek some form of useful, model of the nucleus. Unfortunately, no fixed model exists that is mathematically satisfying in every test.

Enjoy your quest for a nuclear model of the nucleus. Just remember the quantum limit of reality is always there it is the human "dogs" rope limit. It is as far as our examination of reality of space, time and matter can be extended. The mind of man can push the limit built upon theory, experiment and mathematics, but the reality just doesn't exist for us. At what levels of time, space, and matter leaves predictable, ponderable reality is another question for the ages. Way back, time was the chronon, 10e-24 sec. .... The time light took to cross the diameter,(if such a thing exists), of the electron.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.

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Dennis P Brown
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Re: Quantum world views - It's what make fusion happen

Post by Dennis P Brown » Mon Nov 09, 2020 12:19 pm

My daugther did special work on the 'lattice' models related to quarks in the nucleus. I can tell you, that isn't physics or mathematics for anyone who isn't very advanced in those subjects - field theroy knowledge is essential.

That said, the liquid drop is 1940's but still very useful for certain nucliei. The far more modern (and accessible) approch is the shell model as Richard mentions. Protons assoaiate with protons, and ditto for neutrons, forming a series of seperate shells (energy levels) within the nucleus. I've read only bit but there are a lot of accessible articles for amatures up to experts.

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Re: Quantum world views - It's what make fusion happen

Post by Nicolas Krause » Wed Nov 11, 2020 12:08 am

Richard, the book I'm currently reading is arguing that a shell model has an inherent weakness in that the Mean Free Path it assumes for protons and neutrons simply doesn't match the experimental data. Obviously the author is presenting a bunch of data in support of his position, but given the fact that I have zero experience in the field I'm unable to judge whether or not this is a reasonable criticism. Does this track with your understanding of the shell model?

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Re: Quantum world views - It's what make fusion happen

Post by Richard Hull » Wed Nov 11, 2020 4:29 am

Shell models have always had their ups and downs since the 60's. At some point, the nucleus might be understood in some electrostatic and nuclear force balanced manner. There has been talk of an alpha or helium nuclear module model that still holds on in the minds of a good number of physicists.

I have always wondered more in relation to the neutron as the most mysterious component of the nucleus. It solves issues within the nucleus,(beta decay), yet outside the nucleus, it splits into a standard proton and electron within a debatable half life of about 10 minutes.

Ask about why neutrons decay outside the nucleus, but are stable within the nucleus, and the internet will spit back explanations that roam over a lot of ground in a very convoluted post that is designed to leave you still musing over what was just put before you. Unsettling to be sure, but it is mostly a nice pat on the head saying "we don't know for sure", but leave you thinking that outside the nucleus, its mass is to great for its constituent parts so it breaks up....huh?

Yet based on the charge diagram in this posting below, it is known that neutrons, while electrically neutral when observed at range (macroscopically), The neutron viewed at the quantum charge level is indeed a shifting blob of both charges. I have always felt the the neutron is a quantized, crushed hydrogen atom that is unstable in nature, but kept electrostatically stable by nuclear protons about it within a stable nucleus. Once the ratio of neutrons to protons reaches some value, the atom is either stable or emits a beta particle, (electron from neutron decay). This may or may not re-establish the new elemental atom's stability. High Z atoms at Bismuth or above tend to emit entire hyper stable alpha particles. The new atom's resulting from Alpha emission may or may not be stable, emitting a beta particle and so on until a final stable balance of neutrons and stabilizing protons about them cease further decay. Needless to say, a smattering of nuclear gamma rays abound in many of these decays to throw off remaining energy imbalances. It is important to realize that 100% of all extant neutrons are first forged in stars via the ultra rare 10e-13 cross section fusion of H + H and probably +e. After all, there is no more significantly pure plasma, (proton-electron soup), than at the core of a star. The first stable atom is deuterium. Once that is forged and that first neutron is added to the proton, complex matter can be formed from that point on.

Read and try and digest this offering related to the neutron decay issue.

https://www.sjsu.edu/faculty/watkins/ne ... e%20stable.

In the end, be happy that this is all murky for it leaves much to be discovered. Once all the questions are answered, science will cease to exist. Not a good thing.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.

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Re: Quantum world views - It's what make fusion happen

Post by Dennis P Brown » Thu Nov 12, 2020 1:43 pm

An interesting issue for neutrons (free) is decay time. Apparently there is a possible differnce depending on the method used . This may just be an error or might mean new physics.

Can read more at: https://www.energy.gov/science/articles ... n-lifetime

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