[Maya]

Lerner wrote: Actually, what has to balance is force averaged over time to get zero net accleration. In a future generator, we expect 10 GG fields in a roughly 10 micron radius plasmoid lasting several ns and repeated 200 times a second or so. You do the math. It works out to average forces of around a kN–not so much. In other words, huge pressures in a very tiny volume for a very short time works out to not very much average force. But you get good burn up and net energy.

Agreed on these points. What intrigues me most about your approach is the way you are creating magnetic fields, which skirts some serious materials science issues faced in tokamaks.
I’ll read some of those papers and thanks for the pointer.

[Maya]

benf wrote:

66 kJ ? Not even a power figure here? And all for just a “few million amps”!!? You’re killing me over here.

Maybe people don’t want the expensive, behemoth steam driven turbine AC generators anymore after the Fukushima experience and the problems with our grid. So we see the advent of the SMR, the small modular reactor. Unfortunately at this point the trend for those is going to be steam driven turbine AC fission technology.

For a large number of people even a hundred watts is a very big deal. (They aren’t living in ivory towers).

Maybe there is an issue of pressure in any size or form of fusion we could dream up. Great if you have it figured out! Bring the idea to the people in a way that’s
useful to them soon. In the meantime other approaches will have to be tested as well, that’s just reality.

You never know, 5MW could also light up a lot of folks lives.

“For a large number of people even a hundred watts is a big deal”
I think it does not follow that a large-scale production will help others any less than a small one … just because it’s “big”. The question is which approach is likely to actually solve the problem, globally, for everyone?
I hope you’re right that it can be done “small”, cheaply and easily. That would be great. It would be a liberating thing if everyone could just own their own personal fusion reactor and be energy free. That is the ideal scenario. Given enough steps, and if we’re here long enough to do it, I think it will happen.

[Maya]

zapkitty wrote:
… actually, “it doesn’t apply” is a quite acceptable answer when a concept really doesn’t apply …

Rounnnd … and … rouunnnnd. And what we’re looking forrrrr still isn’t found. 🙂
Sorry, it was begging for a use here. Seriously, how about those pressures and reaction force equations?

zapkitty wrote:
Each pulse should generate about 66 kilojoules of gross fusion energy from hydrogen-11 Boron… and yet the physical structure of the device does not support the compression of the fuel. (It did its work holding the device together when a few million amps of current was dumped into the electrodes 🙂 )

66 kJ ? Not even a power figure here? And all for just a “few million amps”!!? You’re killing me over here.

zapkitty wrote:
General Fusion’s rather baroque concept is another way around the “problem”… a sphere a couple of meters in diameter is hammered to create a converging spherical shockwave through molten lead that is spinning inside. When the shockwave arrives at the center the pressure is (hopefully) enough to initiate fusion in the plasmoid hanging in the vortex at the center of the spinning lead… and yet at no time is any point on the outside shell subjected to the immense pressure at the center of the vortex.

And … what locates the hammer? Another way of asking it is, what is accelerating the hammer? What’s holding that?

zapkitty wrote:
Are two examples enough to start?

No, because you didn’t answer the question. In those two examples show me how much force (in the case of a conductor you can start with thermal breakdown) is required to get 100 MW out of that arc (and how much force that plasma will exert against those electrodes at 100 MW). Second, I’d like to know how much force is acting against the thing holding the “hammer”. These are basic, basic questions you should be able to rattle off easily if you’re the proponent (not that _you_ are, but you get the idea).

zapkitty wrote:
Again, each of the fusion startups has their own way of handling the issue.

Right, which works fine for demonstrating that you can produce fusion reactions, but it doesn’t demonstrate economic viability or any semblance of an ability to scale to anything useful.

Denying basic Newtonian mechanics is not a winning strategy if your goal is to figure out the riddle. But we haven’t even touched the other issues. Not to get ahead of myself or spoil an answer to the pressure question but, how about heating and energy transfer? Or what about neutron flux, whether a lot or even just enough to embrittle? Remember, what is 0.1 % of 1 GW? Not really “aneutronic”, is it? I’ll grant you that other schemes do in fact adopt the instabilities to their advantage (Lerner, et al), so I guess that one is fairly tokamak dependent.

[Maya]

zapkitty wrote:

Pretty much irrelevant since ITER and its costs are in no way a design paradigm for a commercial fusion reactor… even a tokamak 🙂

I think that mostly sums up your overall response, so I’ll just respond to that.

Actually, what I said was that for various reasons the limits you envision do not apply to many fusion concepts and I listed some of them and briefly described one of them 🙂

Perhaps you should read through what you called “IP proposals” again… each one has their own way of dealing with what you seem to have come to believe must be an insurmountable problem.

We can discuss the details of their various solutions if you’d like.

By example, if your material is a single-species plasma you can do a fair estimate by just calculating the electrostatic forces between the particles in a given volume. If it is a multi-species plasma you’ll probably want a coefficient to help you calculate the pressure. And the same would be true of other materials. But in every case, the pressure will be enormous. So, for _each_ proposal, as you say, it is incumbent on the proponent to provide that calculation based on their chosen material. They will get a number called Pascals. Then we can all see what it implies.

[Maya]

zapkitty wrote:

Pretty much irrelevant since ITER and its costs are in no way a design paradigm for a commercial fusion reactor… even a tokamak 🙂

I think that mostly sums up your overall response, so I’ll just respond to that.

Actually, what I said was that for various reasons the limits you envision do not apply to many fusion concepts and I listed some of them and briefly described one of them 🙂

Perhaps you should read through what you called “IP proposals” again… each one has their own way of dealing with what you seem to have come to believe must be an insurmountable problem.

We can discuss the details of their various solutions if you’d like.

Right, but my point is that the issue is more fundamental than you seem to realize. In other words, it doesn’t matter what proposal you’re talking about if you don’t know how to calculate and contain pressure.

I don’t think I said the problems are insurmountable. In fact, I was clear to point out that I do not think they are insurmountable. My point is that too many people are ignoring the challenges and it sets the stage for, at best, costly error.

And as for each IP proposal, that is easy. If someone can show me the reaction rate and power density they expect to achieve, and hence the fuel and product density, with their proposal – lets start there – then I’d ask what is going to contain the pressure such a particle density requires. It’s just that easy. It isn’t as though I haven’t asked that question many times. I’ve never gotten an answer to that … not even one that actually addresses that question in the first place. And its a first principles, obvious question, so you can’t say “it doesn’t matter”.

And that was the gist of the author’s article, he just didn’t state it this explicitly.

[Maya]

vansig wrote: i was once asked for some help, by a person who believed his ideas were great, and wanted to share — but please sign the NDA; which i did. and that’s when the trouble started. because perhaps my questions lead to exposing flaws, and my suggestions for fixing them were regarded by the other as ostensibly trivial, and obvious, and not departing from the original intent of the inventor, only a source of greater costs.
i ended up writing large parts of the patent application, without which the thing just would not work; and i was not paid for my input, nor did i receive my name on the final draft.

in my opinion, fraud had occurred, and i am the victim. it was a powerful introduction to the paranoid world of the proprietary, and an important lesson to me, not to allow myself to be trolled by such things.

this forum is for free and open discussion.

if you really want something to exist in the world, lose the need to own it.

Sorry, I couldn’t tell who the user was at first. The system we have is not ideal. But for the same reasons that you are concerned about fraud, I see no other way to do this fairly. If you and your family put hundreds and hundreds of hours of work into an original idea that no one in ivory towers could figure out in decades it is only fair to ask for credit for the invention and fair compensation for your work if someone else is going to make billions off of it. I have no illusions. If the idea worked I would get nothing but crumbs even with patents. But I still deserve compensation for an honest day’s work, especially when so much profit is being made.

As for the NDA, I’m sorry you got burned. You should have gotten credit. What people in academia (who are generally opposed to patents and NDAs) don’t bother to consider is the fact that they are being paid for their work so compensation isn’t an issue for them. I was hoping the forum was also about promoting fusion energy and if it is, people like myself need some way to get a fair shake and share the ideas. So, in that regard as well our system is broken because it is discouraging people like me from ever sharing it. We need a national registration scheme so that ideas can be put out right away and afford protection without all these legal costs and games. So, it isn’t necessarily about “owning” the idea, just a fair way to share ideas.

That’s why I asked for help. Once I have a patent I have no issue with publishing it in the open and I intend to. In fact, I would be crazy not to.

I’m also sorry that people think that because someone simply disagrees with them they are “trolling” or “trolling” for an NDA. How else does one ask for help? How else does one test their ideas in the acid bath of objection and discussion? All this is doing is discouraging advances in fusion. Put yourself in the shoes of someone who has very good reason to believe the ideas they are trying to share are actually sound and significant. What would you do? Do the very same thing you just lamented and ensure non-credit and non-compensation for yourself? Of course not. So an inventor is forced to take an extreme position: act greedy or lose it all, imo.

btw, suggestion. If you do an NDA and end up helping with the innovation …. STOP. And demand a renegotiation. An honest player should be willing to share credit with you.

[Maya]

If you prefer:

Fe12 = κe q1 q2 / r212

[Maya]

zapkitty wrote:

Pretty much irrelevant since ITER and its costs are in no way a design paradigm for a commercial fusion reactor… even a tokamak 🙂

I think that mostly sums up your overall response, so I’ll just respond to that. Apparently I could have said it more clearly. The issue isn’t the particular _way_ you _do_ the fusion, its more fundamental than that. In order to get a power density sufficient to operate a power generation facility you need a minimum amount of fuel in a given volume. Whether it be a tokamak, ICF or whatever. The Coulomb barrier guarantees that in order to get _that many_ reactions in, say, one cubic meter of space, you have to compress that fuel somehow. The forces required to compress that fuel that much are either:
1.) too great to achieve with any known materials science in higher power outputs
2.) too great to make it economically viable in lower power outputs

Even in megawatt class reactors it will take every ounce of cleverness and mass from the periodic table to construct a metallic device that strong. And this first principle observation doesn’t have to depend on what anyone in an ivory tower tells us. We all (or most of us) know how to calculate Coulomb barrier forces, right?
Fm12 = κm q1 q2 * (v1 X (v2 X r12)) / r2
Now, take the reaction rates we all also know about and calculate how many reactions you need in a given, plausible volume, to get the power density you’d need, for, say, a 100 MW reactor. Now, look at F. Its millions of kg*s. The tiny devices being proposed work fine for tiny amounts of fusion and you might well get fusion reactions out of them. But they can’t scale. It’s not my opinion, bad references or whatever. It’s just math.

That’s why these schemes look good in IP proposals: it can be demonstrated as a way to generate fusion reactions but if the observer isn’t particularly mathematically literate they will miss the elephant in the living room.

[Maya]

vansig wrote: you elide heavy with extreme; it is incorrect.

as an analogy, notice that as you inflate a rubber balloon, the pressure inside it falls.

smaller is better

Well, you may be right, but I don’t think so. I mean, in principle, sure it would be better. But in reality I don’t know how you could (economically) build one that is small and at the same time so massive. And I don’t think I have to rely on Ivory Towers to tell me that. If you just look at the Coulomb force, the pressures seen at ITER, etc. it is clear that as power goes up pressure gets unmanageable. Thus more and more mass is needed. If someone could convince me of another route, and there is _one_ I know of, then I’d be persuaded.

So, yea, the neutron flux would be small in a small reactor, but how do you get there? And even then, 1 megawatt of neutron flux will still cause embrittlement and other issues, so I don’t think there will be a “green” or other valuable advantage to offset this bigger cost, at least not as far as the mega-corporations are concerned that would be building these things. All they care about is margin.

[Maya]

vansig wrote: the article ignores aneutronic fusion, yet claims to cover all research. that doesnt add up.

I agree, but I think his point was that the Coulomb force barrier means that fusion generally will require significant pressure or reaction force when the reaction density, and hence the power density, reaches economic levels (even at just megawatts). So, regardless of the type of fusion considered it is very hard to do. Any of these other approaches could work but their machines will be far heavier than they lead us to believe because the pressures, again even at megawatt levels, will be extreme. So, there won’t be a “light, small or cheap” fusion reactor with any foreseeable technology. And that means you have to scale.

[Maya]

vansig wrote: http://i2.minus.com/i1SjC3pAs50Ta.jpg

If a troll is someone who simply doesn’t agree with you then I’ll accept the label. It’s a lot easier to say “troll” than it is to engage the points and explain why I’m wrong.

[Maya]

vansig wrote: Maya,
ITER is a white elephant project designed to convince the world that fusion must be enormous, expensive, probably also dangerous, and always at least fifty years away.
while none of these is true, it looks like you’ve been propagandized.

I don’t think so. I just did the math.

[Maya]

zapkitty wrote:

…?

Could you explain why you think that “at least hundreds of gigawatts” are required for a commercial fusion reactor?

Even the largest current fossil and fission power plants are at most 1-2 gigawatts per unit.

Or did I misunderstand and it’s the fusion concept you mentioned that requires that minimum size to be viable?

Yep, you did. The discussion is about fusion. Which costs more to build and run? Savannah River Site or ITER? And remember how little power ITER will produce. Fusion power plants will be economic monsters that have to be actuarially sound. I think this is part of the problem with the public perception about fusion. There’s a lack of economic reality in the proposals. Iff you could build a fusion reactor that is super cheap, that might change, but somehow I doubt that’s going to happen.

zapkitty wrote:
… a 21 terawatt pB11 reactor?

Why on Earth (and where on Earth) would you want to build a single reactor that would supply over half again the entire world’s current power needs?

It’s about cost and economics. In order for fusion to be seen as a replacement that can idle other plants it must not only produce enough power to justify its cost, it likewise must produce power so abundantly that it expands that market. Do you think that energy consumption will remain constant over the next 50 years? I don’t. I think it will skyrocket.

zapkitty wrote:
The pB11 reaction is aneutronic in nature and units built along the lines envisioned by Focus Fusion, Tri-Alpha and the Polywell concept would be in the scale of a few megawatts to a gigawatt or so and their neutron flux would be pretty damn small.

It seems that you’ve set impossible-to-meet criteria and I look forward to learning what you envision as the solution to them 🙂

I don’t think so. I think the criteria are grounded in hard reality. I don’t believe that megawatt class fusion reactors will ever be economical in any foreseeable future. On this particular point the issue isn’t technical. It’s economic. Why would anyone build a megawatt class reactor that would be such a colossal construction for a single one-off? And the four key issues I described are part of the reason why I don’t think they’ll be economical. Even if you lower the power output you will still have phenomenal pressures to deal with. Have you looked at the structural loading on ITER; a reactor that can barely power a lawnmower? They’ve got the numbers on their website if you’re curious. Even at these totally uneconomical power levels it experiences several million kg*s of force to its structure. These pressure calculations are pretty basic calculations. And before you think that’s just because of those magnets, ask yourself, why do the magnets need to exert all that force? Answer: pressure. Now, given a favorable reaction rate ask how much fuel product must be present to get a worthwhile power density in the plasma and you will see my point. As you pack the material closer and closer the pressure necessarily goes up. Power and pressure have a defined mathematical relationship in thermonuclear fusion and they scale together as a square.

Yes, I know, youtube is replete with one venture capital con after another talking about producing fantastic amounts of fusion power with virtually no mention of pressure. But that’s not reality. It’s fiction and IP games. If that doesn’t make it clear, you can also run a power calculation and estimate equivalent reaction force against the vessel. That will also make it clear. It doesn’t matter how you _do_ the fusion. The problem here is more fundamental than that. Fusion at bottom is a power conversion problem of a magnitude of which the public is not generally well aware.

In the case of fission plants producing 1 or 2 gigawatts, the energy transfer is through very large, very heavy turbine machinery that distributes what would otherwise be pressure on a fusion reactor vessel. But, it’s still only a couple of gigawatts. But more fundamentally and to my point, fission doesn’t rely nearly as much on pressure (or reaction forces generally) … because its fission … not fusion.

If you have an Ph.D in physics and will sign an NDA I’d be glad to share my thoughts on a solution with you. I’m not being hokey or pessimistic at all. I believe there _is_ a solution, but it’s not on youtube and there is a lot of incentive out there to sell intellectual property instead of creating fusion power. If we’re going to solve the fusion riddle we have to understand what the technological impediments actually are, and very few people do. Sadly, academia isn’t helping because they want the big bucks for what they well know is nothing but pure science with no near-term application merit. That’s my take on con-Fusion Wonderland.

[Maya]

AaronB wrote: Hi Maya. I review ideas like this a couple of times per year for investors, family, and friends. NDAs aren’t a problem for me. I’d be happy to look over the technology and let you know whether it seems viable or not. Besides being viable, it has to be marketable. I’ll be brutally honest in my assessment, just so you know, but that doesn’t mean I just look for the bad. I look for the potential also. Applying for and receiving a patent is a long and expensive process, and you have to decide whether the technology is worth it. Just send me a private message if you want.

There’s no indication that it was sent, but I just pm’d you. Thanks a lot – mk

[Maya]

AJSA wrote: Perhaps somebody could explain in the blog a bit of Focus Fusion Technology.
As I can see the posts are very biased…

http://physics.ucsd.edu/do-the-math/2012/01/nuclear-fusion/

It looks like we have two threads going on this, so I guess I’ll post my reply here as well?

This is the first published description I’ve seen so far that accurately lays out the key challenges of fusion power. Notice that not one single proposal in existence today deigns to address them. Contrary to the view of some, I think we rather should talk about these problems not as discouragement but because that is the only way we can solve the riddles. If you don’t know what the challenges are you can’t find the solution. I can summarize the key 4 issues with fusion power that must be addressed for a _commercially viable_ (at least hundreds of gigawatts) reactor to work:
1.) It must have a much more powerful means of “heating”. RF and other methods are woefully inadequate
2.) It must contain enormous pressures far beyond what any material science we have can contain (the author refers to temperature but the two are related)
3.) It must deal with the thermal management of neutron flux. The current fueling schemes will never work. Only Hydrogen and 11 Boron can be used in any foreseeable design and even that will require enormous thermal management (H-11B still produces flux in power levels of 1 to 10 giga watts in a 21 TW reactor).
4.) It must have a definitive mechanism for dampening out _all_ orbital instabilities in the plasma. Confinement time must be very, very large b/c the materials science cannot deal with it otherwise.
Part 2 has a clever, witchy exception that as far as I know no one has figured out yet.
If you have a Ph.D. in physics (any field) and will sign an NDA I’ll explain it … I hope.

[Author]

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