Dr Park speaking at University of Maryland on September 9th

[ladajo]

I think the thing I like most about the San Diego lab is the bits and pieces of EMC2 history that litter the upstairs.
Well, to be fair, the lab floor is purdy darn cool to poke around.

I am just glad that Jaeyoung is making the rounds and getting the word out on what he has.
It will be interesting to see how things play out over the next 6 to 9 months.

[mvanwink5]

This is what I am talking about on "How to get funding." It is more than a breakthrough published research paper and then some VC will swoop in with cash like the winning lucky lotto pick numbers and drop the cash, just throw Park out there and do some fishing. No. Look what the WSJ says about Helion:

http://blogs.wsj.com/venturecapital/201 ... RDS=helion
VC Funding, Y Combinator Power Up Nuclear-Fusion Co. Helion Energy

“If our physics hold, we hope to reach that goal in the next three years,” said Dr. Kirtley. Helion, which was incorporated in 2009, has been working from internal funding and $7 million in Energy Department and Department of Defense grants thus far, the CEO said. (It did attempt to raise venture funding back in 2009, but then decided to turn to internal and government funding, according to Dr. Kirtley.)
The company found believers in its new investors.
“We’ve come to the conclusion that fusion was not a crazy idea,” Mr. Royan said. He said Mithril’s team has reviewed various nuclear-power technology developers and approaches. One of his requirements for backing a technology company in the space is that “there should be no miracle physics requirements, no immaculate conception.”
The team at Helion has come further than any other nuclear startup in developing a working model that Mr. Royan said could “with a reasonable degree of assurance” scale into a project that would produce electricity at a price below that which is derived from natural gas. He said the team has an entrepreneurial approach, caring for the way the resultant product would look and why it would be accepted in the market, and caring about costs and other aspects that scientific-minded teams typically leave aside.
Mr. Royan said that when he met Helion’s CEO he was impressed by the jargon that Dr. Kirtley used, such as “product road map.” “You are talking like a software guy,” Mr. Royan said he told the CEO.

Don't take my word for it. See what worked for others...

[Betruger]

It's still just marketing. EMC2 might have lacked foresight (to this ostensible new VC period), but with the Navy I don't see why it was wrong to simply work the substance rather than anything accessory to it. A good product sells itself. A working, useful fusion reactor trumps all the marketing in the world.

[paperburn1]

It's still just marketing. EMC2 might have lacked foresight (to this ostensible new VC period), but with the Navy I don't see why it was wrong to simply work the substance rather than anything accessory to it. A good product sells itself. A working, useful fusion reactor trumps all the marketing in the world.

I think you may have hit the nail on the head as to why the navy backed out.
A working, useful to the navy fusion reactor trumps all the marketing in the world. If they found something that made polywell unusable to the project the navy wanted they would stop funding. No mater how useful it could be otherwise.

[mvanwink5]

Everything we have heard so far would indicates Polywell would be useful to the Navy though. The simple answer is that EMC2 couldn't finish WB-8 with the original budget as the e-guns needed did not fit the budget. Not the first time budget failure ended a project.

[Betruger]

As compelling as that is, paperburn, I have to agree with mvanwink: history's full of these incredible non-sequiturs.

[AcesHigh]

I wonder if the navy wasn´t convinced by Lockheed Martin to scrap EMC2 and invest in LMs fusion concept?

We all know LM has other contracts with the navy and probably hundreds of connections on all levels.

[D Tibbets]

I wonder if the navy wasn´t convinced by Lockheed Martin to scrap EMC2 and invest in LMs fusion concept?

We all know LM has other contracts with the navy and probably hundreds of connections on all levels.

I have no idea what the Navy plans. But the LM public claims are attention getting, both publicly and institutionally- Defense dept. and mainstream nuclear fusion community.

Lockheed Martin Skunkworks has a well earned reputation for innovation and 'can do' attitudes and management. Plus, it is a big player on the military industrial complex stage. It is more difficult to dismiss claims coming from them compared to all of the other alternate (hot) fusion efforts like Polywell, FRC, etc. The mainstream tokamak crowd has to take them seriously, not just ignore them or gag them with restrictive shoe string budgets.

I sometimes wonder if much of the funding provided to Bussard was motivated as much to keep him from making waves as it was to further fusion research.

Dan Tibbets

[ladajo]

http://nextbigfuture.com/2014/10/emc2-p ... .html#more

Interesting article comment about not charging the Magrids.

[D Tibbets]

http://nextbigfuture.com/2014/10/emc2-p ... .html#more

Interesting article comment about not charging the Magrids.

I am gaining an appreciation of why a neutral magrid may work for recirculation issues. I have not seen why a positively charged magrid is bad. I'm guessing that if this is so, it has to do with electron injection efficiency. Either that or Gauss's law considerations within the Magrid is not as absolute as desired (due to size of openings) so that internal electrons and ions are not completely immune to the magrid charge. I suppose that the strong electric charge on the magrid could also pull electrons towards the side as they are closest to the magrid surface (such as in the corner/ line cusp areas). I think this would require some defect in geometry to be significant, but how much ? If one side protrudes 1.0 mm or 0.001 mm closer, is this enough difference to be significant? If it is a problem, even slight at 10,000 Volts, it would be magnified at 100,000 volts. The same could be said of the high voltageelectron guns also. If they are misaligned by a small fraction of a degree it may effect injection efficiency.

My current appreciation of electron injection is that it is poor and this is due to external mirroring of electrons. Those off axis enough in position or vector will be mirrored. Very good collimation of the electron injection beam helps, but beam spreading of this intense electron stream is unavoidable without continuous active focusing. This may have other unfavorable consequences, though considering WB5 and WB6 the positive charge on the magrid seemed to be the least intrusive for internal electron and Ion containment. My concept that the positive magrid helps to focus the electrons as they approach the critical mirroring region may or may not be reasonable. But, with the positive magrid, so long as it is magnetically shielded, and there are no exposed high voltage nubs, the mirrored electrons will give their energy back to the magrid and thus not be a major energy drain. With high voltage electron guns spaced well outside the magrid, any electrons mirrored back will mostly end up grounding on a neutral surface, there is no recapture of the electrons energy. Thus losses are what ever VA is emmited by the E guns minus that portion that gains entry to the interior. From a energy balance the magnetically shielded positive magrid would seem to have a great advantage. Of course the injection efficiency plays a role, but the balance is the important point, ignoring possible issues like external arcing due to exterior density.

I can speculate on further considerations about injection and recirculation interactions, but not now.

Except for
PS: I will add that with the positive magrid like WB6, the escaping electrons that are not upscattered will stop and reverse back through the same cusp. These electrons are briefly cold and could act as an electron plug. If this occurs too close to the magrid it could have consequences like WB5 where this collection of cold electrons near the magrid mid plane was too attractive to ions*. The effect , while not as obvious as in WB5, might be detrimental. Looping around to enter another cusp, the electrons remain hot with the neutral magrid. But what about the interaction with inbound e-gun electrons.....

* an indication that Gauss law considerations may not be absolutely dominate in this system.


Dan Tibbets

[Tom Ligon]

The idea that a "cold electron plug" could form in cusps occurred to me when PXL-1 taught us a severe lesson one day. While repairing the damage to equipment that could not possibly have been damaged by the event, but was, I thought that might explained why this particular, supposedly leaky at the cusps, and lacking a charged magrid, machine could have evidently nonetheless stored a boatload of electrons at considerable energy.

Hence, my fascination with one day revisiting that machine.

I've been assured by several people that my hypothesis is hogwash. But nevertheless, I think the machine was trying to tell us something.

[AcesHigh]

http://nextbigfuture.com/2014/10/emc2-p ... .html#more

Interesting article comment about not charging the Magrids.

can someone answer that Raahul Kumar guy at NBF??

People, I read NBF to discuss technology. I suspect most of the people reading this topic are interested in fusion, can we get back on topic?

We constantly read a lot about fusion at NBF. And the problem with this article and many other fusion articles is that it disregards the enormous physics challenges ahead. Compared to JET, Polywell approach isn't even close. The major issue, and I contrast with ITER, is that fusion is hard to simulate on computer. ITER, on the other hand, has scaling laws based on experiments. These do work, and allow the consortium to proceed with the lowest risk approach confidently.

The Polywell approach is a lottery ticket. You *MAY* win millions. The likelihood is that it will fail. All the progress to date doesn't even come close to where Tokomak fusion research was decades ago. All fusion approaches need to be assessed by how well they meet Lawson Criterion.

http://en.wikipedia.org/wiki/L...

It's a magical formula that captures everything important to a fusion reactor in one equation. Always ask, how well does it meet the Lawson Criterion compared to ITER?

"The genesis of Lawson's Criteria is simple enough—he calculated the requirements for more energy to be created than is put in, and came up with a dependence on three quantities: temperature (T), density (n) and confinement time (τ)*. With only small evolution thanks to some subtle changes of definition, this is basically the same figure of merit used by today's fusion scientists, the triple product, nτT. "

http://www.iter.org/newsline/2...

The triple product for polywell is dismally bad. It's a nonstarter, there will be tokomak fusion reactors producing energy on the grid before we *might* ever see a Polywell. We might never either, it's unclear if it will work. I'm not saying it's against the laws of physics,
I'm saying it's uncertain if it will or won't.

[ladajo]

My resonse to him would be to ask him to show the triple product for Polywell. And show it over experimental iterations in the program.
The bottom line is that I wager he does not really know where it is or where it is headed.

In summary, with out going number crazy:
Polywell Lawton Criteria
(T) - Controlled by well depth. Previous machines have demostrated ample ability to accellerate ions. This is the next step for the current (WB8 based) evolution of test machines.
(n) Again, a function of well depth and also sustainment.
(τ) This one is a little more interesting in my book. I rate it as mostly dependent on well depth, as well as geometry. Here I think Polywell has an advantage. Especially with the removal of the nubs and improvements in ability to control the plasma.

The point here is that your poster over there is thinking in terms of fuel. Polywell is a hybrid. You need to think in terms of electron plasma and fuel, like a fusor. The Lawson criteria was not envisioned for these types of machines. So you have to shoe horn it to some degree to make it a usable gauge.

He is also leaving out cost and resources side of the argument. Sure, we can probably build ITER and make it work. But it will be a long time (century or more), if ever, that it will be an economical approach. We could send men to another star today. But the cost in blood and treasure is well beyond anything we can muster, and the gains are suspect given that. The scale of the project to get a meaningful output (breakeven) as a concern seems to be outside his ablility to reason.
Such is ITER.

[D Tibbets]

ladajo pretty much covered the question. But,to add to the answer ...

Lawsen criterions are straight forward, but there are assumptions that change things some.

With the Polywell the average temperature verses the thermalized distribution is a factor that favors the Polywell considerably, especially when you move beyond D-T fuel. Not only is the fusion rate different , but the Bremsstruhlung contribution can be different. There are other considerations concerning Bremsstruhlung also. With a mono energetic energy distribution (marrow range around the average temperature) almost all of the fuel can participate in the fusion production, not just a small thermal tail well above the average temperature in a Tokamak.

Containment time is a consideration that has been misunderstood as well. The tokamak has confinement times of up to hundreds of seconds. It may eventually exceed a thousand seconds. The ion confinement time in the Polywell may be only 10's of milliseconds. At first glance this seems dismal. But in relation to the Lawson criterion, it has to be compared to temperature and density to determine the triple product. Fusion scales as the square of the density. So if density can be increased 10 fold, the confinement time can be 100 times shorter. If the density can be increased 100- 1000 times, as is the applicable comparison between Tokamaks and Polywell, the fusion rate will be 10,000 to 1,000,000 times faster with comparable reductions in necessary confinement times. Keep in mind that Nuclear bombs have confinement times of only a few 10s of nano seconds, yet they achieve considerable fusion output because of the corresponding density. 1000 sec confinement time in Tokamaks is comparable to as little a 1 millisecond ion confinement times in a Polywell.

Nobody really challenges that electrostatic acceleration can heat the ions to adequate temperatures. Heating in a Tokamak is much more difficult.

I suspect that ion confinement and heating in a Polywell is not much of an issue. What is the issue is the effort required to inject electrons into the system, and their confinement time. Now that high Beta operation has been demonstrated the major argument against the Polywell is minimized. Other issues that may greatly favor the Polywell is that no diverter is needed, no lithium blanked with all it's untested engineering challenges is needed. The size and strength of the superconducting magnets is very much less dangerous. A accidental quench in a superconducting magnet would result in damage comparable to that which occurred in the Large Hadron Collider. If the same happened in ITER or DEMO or a production Tokamak, the resultant explosion could destroy the entire multiple billion dollar plant. There are work arounds, but they are expensive and challenging. These are a few of the reasons that the Polywell and other smaller machines that are not dependant on D-T fuel, have less uncertain barriors to overcome. The simple size of the machines also dictate much of the cost. I personally suspect that JET and other Tokamak machines have reached the stage in Tokamak research, that achieving Q> one is almost certain. But at what cost? And, what additional cost to actually make a working power producing plant? The cost of these smaller machines- Polywell, FRC, DPF, even General fusion, both for research and projected working models is on the order of 100 to 1,000 times less. Applying mathematical models for cost * risk versus projected benefit has to favor these small machines, provided the physics is at least defensible. And they have certainly been attacked on the basis of accepted physics and have stood up to the test thus far, up to the point where only experiment can resolve the contest.


Tokamaks have certainly generated a huge set of data and predictions. One of the major problems though is the complexity that requires such finesse. The edge instabilities, MHD instabilities in the Tokamak and other approaches are a major consideration that limits capacity, and requires fine understanding and manipulation to minimize. One often ignored(?) aspect of the Polywell and a few other approaches is the edge stability that is straight forward and requires little consideration.

One admittedly short coming of these small machines is that they are primarily private ventures and have not released a lot of information. One advantage is that they are relatively small efforts with relative quick evolution potential given only modest money. The often quoted saying that 'Fusion is only 40 years away and always will be' has to be modified to 'Fusion is only 5-10 years away and always will be'...

Dan Tibbets

[ladajo]

Here is further thought on Lawson Criteria for Polywell courtesy of Jaeyoung Park;

"In high β cusp, plasma confinement time is sufficiently long to satisfy Lawson Criteria without the need for non-Maxwellian distribution. "

Theoretically conjectured loss current per cusp by Grad and NYU team:

I e,i / e = π / 9 * n e,i * υ e,i * π(r e,i ^ gyro)^2

means: 0.5s confinement time for 100 keV electron with 7 T, 1m radius 6 coil cusp which is favorable for a net power device.

So what is:
- 100 keV e-injection: τ e ~ 0.5 sec per Grad for 1 m device (longer τ for larger size)

- β=1 condition, therefore plasma density of 1.2x10^15 cm-3 at 7 T magnetic field

- If Polywell can achieve 30% efficiency of converting electron beam energy to ion energy via electric potential, T ion ~ 30 keV.

Polywell nTτ ~ 1.8x10^16 keV s/cm3 > Lawson triple product of 1-10x10^15keV s/cm3
and, it is also noted that Polywell does not require alpha heating to achieve net power"