A Sequel to The Google Talk

Point out news stories, on the net or in mainstream media, related to polywell fusion.

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Tom Ligon
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Re: A Sequel to The Google Talk

Postby Tom Ligon » Fri Jan 30, 2015 8:30 pm


mvanwink5
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Re: A Sequel to The Google Talk

Postby mvanwink5 » Fri Jan 30, 2015 8:48 pm

I would suggest that this was obviously not a business proposal, just a talk to an interested group. So, drawing business conclusions would seem to be a really great leap. Given that, it does seem like some serious discussions are being made and that is encouraging, (from the point of view of the nose bleed section of the bleachers.)

In so far as proposals, at no cost to myself, I'll defer to others who likely have better insight than provided by my stadium seats.
Near term, cheap, dark horse fusion hits the air waves, GF - TED, LM - Announcement. The race is on.

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Re: A Sequel to The Google Talk

Postby D Tibbets » Fri Jan 30, 2015 9:20 pm

To error is human... and I'm very human.

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Re: A Sequel to The Google Talk

Postby MSimon » Fri Jan 30, 2015 9:49 pm


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Re: A Sequel to The Google Talk

Postby Tom Ligon » Fri Jan 30, 2015 10:54 pm

You folks all have your copies of the NRL Plasma Formulary handy, right? I know you do because the Polywell is pretty much designed straight from it, and RWB was forever going to the board with a piece of chalk in one hand and the Plasma Formulary in the other. If you have somehow neglected to get one, you can download it after a quick web search.

Various editions have different paging, but the section to look for is Fundamental Plasma Parameters. On my 1994 edition, this section starts on p 28, and down at the bottom of p 29 is "Magnetic pressure is given by ..." Well, heck, I'll be darned if it does not give the results in atmospheres. I mean, of all the cockeyed units one could pick for a physics handbook!

But then again, the units involved are B in kG or Teslas, and I see dynes and cm in there. 8 pi is a dead giveaway that there is a cgs/SI units mismatch to compensate for. And the result in atmospheres.

The old physicists like RWB used this conversion mismatch stuff all the time. It must drive the youngsters nuts. Worse, we'd sometimes stick in a few English measurements just for fun.

Anyway, Pmag goes as the square of B. 3.93 (B/Bo) ^2 gives atmospheres where Bo is a Tesla or 10 kgauss depending on your choice of units. For B = 5 T you do indeed get 98.25 atmospheres. Complicated somewhat by where exactly your 5T is, because magnetic fields are devilishly complex, particularly when squished together with a squirming diamagnetic plasma pushing them back. But as long as you have the stable cusp geometry and don't overwhelm it, a happy medium should be found.

Now compare that units system to dynamic pressure (used in aeronautics) at speeds less than 1/3 Mach.
Dynamic pressure in Pa = (Ro V^2)/2, where Ro is density in kg/m^3 and V is in meters/sec. No funky units conversion ... the SI units just make it fall right out. It even works supersonic if you are careful ... it has to be a simple case like a blunt body.

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Re: A Sequel to The Google Talk

Postby mvanwink5 » Sat Jan 31, 2015 12:07 am

Near term, cheap, dark horse fusion hits the air waves, GF - TED, LM - Announcement. The race is on.

D Tibbets
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Re: A Sequel to The Google Talk

Postby D Tibbets » Sat Jan 31, 2015 2:55 am

To error is human... and I'm very human.

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Re: A Sequel to The Google Talk

Postby Tom Ligon » Sat Jan 31, 2015 3:50 am

One of the things to come out of this is that Dr. Park seems to have switched to e-guns rather than attempting to use the magnets as an accelerating structure (magrid). There's a long line of reasoning that led to the magrid idea, and I've done my share to reinforce it, but it may have been a bad idea.

Farnsworth did NOT use grids, he used ion guns. Hirsch realized he could do the same thing with a grid structure, but of course we know the limitations of the Hirsch-Farnsworth fusor.

We've been treating the Polywell as a magnetically-insulated Elmore-Tuck-Watson machine, talking about diamagnetic wiffleballs, using the convex field stability principle, but not giving Grad enough credit. Thinking of it as an Elmore-Tuck-Watson machine makes one think in terms of using the magnets as a magrid. But then it opens you up to all sorts of nasty discharges that terminate the run, and maybe other disadvantages. If you trigger ionization outside a magrid, you're doomed -- the Paschen discharges that terminated the WB-6 runs.

The little cusp confinement machine kinda gets back toward Farnsworth (but with e-guns rather than ion guns), and it also throws a lot of emphasis on Grad's contribution, pure cusp confinement and the diamagnetic zone.

One thing I've said here for a long time is that PXL-1, which had the polyhedral magnets but on the outside of the chamber, lacked a magrid, yet did some really fascinating stuff, including storing a huge amount of energy that caught us by surprise when we cut the magnets too early. And it used an e-gun. It did develop a small glow-ball in the center when we had it running nicely, but the most we could feed it was around ten kW. I now suspect it was forming a wiffle golf ball, and in fact I probably saw the thing once or twice. Kicked with a short pulse in the 100's of MW to inflate a real wiffleball, that rascal might have done something. Field strength on PXL-1 was comparable to the small cusp test machine. WB-5 was a similar geometry to PXL-1. Dr. Bussard kept coming back to the idea (HEPS, PXL, and WB-5) ... likely he was on the right track but was not understanding the startup power required.

I was never really the expert on these things ... I just hung around and bent tin for them. But I think Dr. Park has his head wrapped around this thing now, probably better than Bussard. Furthermore, going back to Dr. Krall's papers back in the DTI/HEPS era, I think Krall probably does as well, and may have had it pretty much right in the '90s. And that was e-guns. Electrodynamic fusion is still promising. But what's the best way, guns, or a magrid? Maybe both. But maybe not all magrid.

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Re: A Sequel to The Google Talk

Postby ohiovr » Sat Jan 31, 2015 4:04 am

How in the world do you go from atmospheres in to what tokamacs, polywells, and IEC devices use? Are we talking about the fuel dispersion? Fuel plasma I mean. I mean the 100 million degree K plasma. Yeah that stuff. Power increases by the square of the density. So I'm told. Anyway lets say the density of ITER is 1/10th of an atmosphere and produces roughly 500 kilowatts per cubic meter. Sure I know the density is far lower than that. But for the heck of arguing lets see what happens when we have an 100 million degree K atmosphere composed of deuterium and tritium same as ITER, however the pressure (or density) is 980 times more. Here are some crude calculations:

500,000 watts per cubic meter * 980 * 980

I get

480,200,000,000 watts

That's 480 Gigawatts, per cubic meter. But wait.. there's more.. The reaction volume is even bigger than one cubic meter!

And Iter sure as hell has less pressure than 1/10th of an atmosphere! Lots less

Oh maybe the presenter was just boasting.. like saying we could do that kind of pressure if we really wanted to.

Nope! Even if you really wanted to, that container would evaporate. And its supposed to have cryogenics within centimeters of the reactor volume. Man..

But..

There is plenty of time to restate what the expectations are. Misprints and all...

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Re: A Sequel to The Google Talk

Postby mvanwink5 » Sat Jan 31, 2015 5:08 am

They are different machines. In Polywell, the pressure referred to in Dr. Park's presentation is generated by the electrons at the boundary of the plasma where it meets the magnetic fields (remember the magnetic field is excluded inside the plasma due to diamagnetism) and not by the ions which have a different kinetic energy profile (slow at the electron / magnetic field boundary and fast at the plasma center - bottom of the potential well). Therefore your analysis is missing the dynamics of the plasma in the Polywell.
Near term, cheap, dark horse fusion hits the air waves, GF - TED, LM - Announcement. The race is on.

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Re: A Sequel to The Google Talk

Postby Tom Ligon » Sat Jan 31, 2015 4:33 pm

Time for a little tokamak primer, I think. Not from me, from an actual expert.

As I stated above, but maybe you missed, magnetic pressure is a function of magnetic field strength. straight out of the NRL Plasma Formulary, which gives the result in atmospheres. Evidently nobody dares change this archaic unit that has been adopted by fusion researchers since, well, a long time.

If you are working in Teslas, 3.98 B^2 gives magnetic pressure in Atmospheres. So at 5T that works out to 98.25 atmospheres. Straight from the Plasma Formulary.

If you intend to operate at beta = 1, then by definition, plasma pressure MUST equal that. If it cannot, then you're not at beta = 1. Which appears to have been the case in ALL of RWB's work, regardless of what he thought. He was stuck at a much lower beta. But Dr. Park got to beta of about 0.7. It takes a pretty big hammer.

Tokamaks work at a much lower beta, too. Just what that beta is will depend on the particular machine and the experiment, but evidently 0.05-0.08 is considered pretty good. Magnetic fields quoted vary quite a bit as well. We've been hearing about 12 T magnets but they're not always that strong. Tokamaks dare not approach beta = 1 due to the plasma pushing against concave fields, which are unstable.

So lets look at some sources of data here. We'll start with Prof. Cowley, director at JET.

http://www.psfc.mit.edu/library1/catalo ... cowley.pdf

We'll see he uses the same formula for magnetic pressure (rounds 3.98 off to 4) and puts beta on ITER at 0.08, and the axial field at 5.2T. He shows fusion power as proportional to the square of plasma pressure. If you look at slide 7, he puts magnetic pressure at 100 atmospheres, and plasma pressure at about 7 atmospheres. Mind you, this is in a 20 keV plasma. I'd think it a stretch to just say to apply ideal gas law extrapolated to 100 million K, but obviously we're not talking about 7 atmospheres of D-T at room temperature. Cowley shows us that fusion power increases by the square of plasma pressure ... he wants all he can get.

So, yes, the magnetic pressure cited in Dr. Park's talk at 5T is correct. To get to beta = 1, by definition, plasma pressure must equal that. It can be higher than a tokamak because the convex field structure of a Polywell's cusps are stable ... they compress back like foam rubber and stiffen up as they compress, if that helps you picture it (that's my analogy for science fiction audiences).

That leaves the question of can you get to beta = 1? Bussard did not. Park and his crew of loyal hunchbacks figured out how, or at least how to get pretty close, and they injected power on only 2 of the cusps.

Now the question is, does it scale? Can this be pushed to work on a 5T, 2 meter radius machine, and achieve net power? What intermediate steps, if any, are needed? We know Dr. Bussard would have jumped straight to full scale if allowed to. We know Dr. Park has an intermediate in mind. Neither Bussard nor Park proposed hanging electrical power generation equipment off the machine before demonstrated net power.

Now the question is, is the cost reasonable, and can funding be found? GIThruster thinks $300 million is a deal killer. My opinion is, if this were 1805, $300 million would have been a deal killer. Today, I have to ask, what technologically savvy superpower could NOT try this? I can understand that there are a lot of capitalists out there who would rather invest in Shake Shack or Box. Me, I have a Box account, it is crap, and I would not invest in the company. And fast food is beneath my dignity as an investor.

I said it before, and I'll say it again. If I had ... OK, the number is up since my last pronouncement ... $300 million to spare, this thing would be funded already. (Ligon sadly opens wallet and sees $28).

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Re: A Sequel to The Google Talk

Postby GIThruster » Sat Jan 31, 2015 4:45 pm

"Courage is not just a virtue, but the form of every virtue at the testing point." C. S. Lewis

Tom Ligon
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Re: A Sequel to The Google Talk

Postby Tom Ligon » Sat Jan 31, 2015 5:19 pm

I knew this would be your answer, GIT. This is the same business model on which you say a UAV that can fly faster than 30 kts is a waste of money because you could do the same job with a park-flyer foamy bought in the Walmart toy shop. (Ligon hides behind a desk so as not to be hit by the objects about to be thrown. :) )

I understand. Really, I do. I'm a cheap SOB myself, and probably would try to poor-boy a cheaper solution. I cringe when I hear what some of these big physics projects spend on hardware.

Everyone complains that fusion is always 20-30 years away. But a consequence of that is that we have a number of people working on it who have 60 years of experience to draw on. They've now got a pretty clear picture in their heads of how may $ it takes to build a tokamak. Might it be possible to find a somewhat cheaper way to do it? Probably. But honestly, a 90% cut would destroy any hope of even the poor boys doing it. If labor were the main cost, it might mean China or India could still have a chance (they can build space hardware cheaper than we do.)



The plain and simple fact is, based on size and tonnage of what is essentially a re-arrangement of similar components, those estimates should apply pretty well to a Polywell. The difference is that the Polywell is a lot smaller, so it will cost less. This fact alone should be enough. Here's a project with world-changing potential, a lot cheaper than an approach already underway that requires multiple nations to fund it, cheap enough that it actually can be pursued by a wealthy individual or a relatively small group of investors. The potential payoff is enormous.

It is not for everyone. GIThruster's checkbook is hidden soundly under his mattress. I could be a small time contributor but that's the limit of my resources. But with 6 gigapersons on the planet, and 1% of those supposedly owning about half of everything, probably there is a handful out there with a different assessment of the situation. And that is all it takes.

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Re: A Sequel to The Google Talk

Postby GIThruster » Sat Jan 31, 2015 5:37 pm

Tom, take a moment and roleplay the position of the investor.

You've got these guys working about a decade now with almost no funding that have made remarkable headway. Their approach shows great promise. They are one of half a dozen approaches, and pretty much in the lead, but the other approaches have better financial backing and larger, smarter teams working their problems.

Poly scientist comes to you and says "hey, we needed to solve the electron thing and we did. Now we need to solve the proton thing. After that we need to solve both together. Then we need to operate continuously. Then we need to scale to commercial size." He is 4 steps from commercialization and each step represents its own risks. Note too, this team has already failed so far as being a team. The team leader has been replaced twice--the first time by a death and the second time by attrition. That attrition is a HUGE red flag for any investor.

Now said scientist tells you that despite he is not ready to build a prototype, nor even a machine that can operate continuously; he wants $300M.

Try not to laugh nor spray your coffee across the room.

Just saying, you folks need to wake up and smell the coffee. Real life does not operate the way you seem to think it does. No one is going to fund the Poly for $300M at this stage, except unless there is an act of God through Congress. That would be a first, wouldn't it? Is that what you're holding out for?

Just saying, there needs to be a completely different approach to funding taken and it appears there is no one involved here who has the slightest idea what they're doing. They should be putting together a proposal for a very few million dollars and 2-3 years with very specific, achievable goals and they're not doing it. Either EMC2 gets their shit together or the whole Poly project will go belly up. They cannot get traction making these kinds of mistakes.
"Courage is not just a virtue, but the form of every virtue at the testing point." C. S. Lewis

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Re: A Sequel to The Google Talk

Postby MSimon » Sat Jan 31, 2015 5:44 pm

This is what VC looks for:



Text version:


Smart is a given. After that #1 on the list is determination. But read the whole thing.


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