EMC2 news

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

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ladajo
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Re: EMC2 news

Postby ladajo » Sun Sep 20, 2015 12:38 pm

For net profitable fusion electricity production a Q >5 may be needed.


Q=10 or better is the tabled target for a viable plant. Q=5 is the target for self sustaining research plants.
Obviously these numbers are a little fungible as we get smarter.

Q=1 is the current feasibility target. Once we cross that line, all the other arguments become real, and not theoretical.
The development of atomic power, though it could confer unimaginable blessings on mankind, is something that is dreaded by the owners of coal mines and oil wells. (Hazlitt)
What I want to do is to look up C. . . . I call him the Forgotten Man. (Sumner)

Skipjack
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Re: EMC2 news

Postby Skipjack » Sun Sep 20, 2015 8:13 pm

D Tibbets wrote:The problem is the praticality of the aproach. This can also be applied to the ITER Tokamak approach.

I fully agree with you on that, Dan.

D Tibbets wrote:The other example is the NIF, sort of, if you ignore many aspects. The laser input that directly contributed to compressing and heating the DT fuel was less than the fusion output. This does ignore the laser energy that expended doing other things, like heating and exploding the horloium (sp?). Only a small portion of the laser input contributed to the DT compression and heating.

Yeah and lets not forget what went into making that "Hohlraum" in the first place...

D Tibbets wrote:Any benchmark is open to interpretation.
A Q>one is not useful for energy production, actual performance would actually need to exceed a Q>3 or so for a net positive electricity generation via a steam cycle. As such, that is the real minimal target. For net profitable fusion electricity production a Q >5 may be needed.

Direct conversion has the potential to help a bit with the conversion efficiency and overall economy of the powerplant (if we can get it work), otherwise, ladajo is right and a Q>10 might be needed.

D Tibbets wrote:In some situations a Q < one may suffice.

I think a good example for that would be fusion-fission- hybrids.

Skipjack
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Re: EMC2 news

Postby Skipjack » Sun Sep 20, 2015 8:18 pm

ladajo wrote:
For net profitable fusion electricity production a Q >5 may be needed.

Q=10 or better is the tabled target for a viable plant. Q=5 is the target for self sustaining research plants.
Obviously these numbers are a little fungible as we get smarter.
Q=1 is the current feasibility target. Once we cross that line, all the other arguments become real, and not theoretical.

Agreed, a Q>=10 is at least needed if you want to have a steam cycle and still be economic. Some say you need as much as 20 for it to be competitive with coal.
Q>=5 is the target for ITER, but they hope to get as high as 10 with it. DEMO will show a Q of 20 or more and will also have to demonstrate Tritium breeding and energy extraction and conversion. The Q is only of academic value without the means to convert it in to usable energy.

CherryPick
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Re: EMC2 news

Postby CherryPick » Mon Sep 21, 2015 2:52 am

Do not forget the need for heating. More than half my electricity bill goes to keep us warm during winters.

Fear of nuclear makes us waste most of the produced energy. The city of Helsinki uses coal instead of heat of nuclear power from Loviisa, 90 km east. It is easier to create image of safety to fusion than fission, because the technology is different. Remember here the Greenpeace principle that image is more important than facts.

hanelyp
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Re: EMC2 news

Postby hanelyp » Mon Sep 21, 2015 3:09 am

Compact fusion reactor in the basement of a skyscraper in a near Arctic region? Providing both electricity and central heating.
The daylight is uncomfortably bright for eyes so long in the dark.

choff
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Re: EMC2 news

Postby choff » Sat Oct 31, 2015 9:03 pm

There's been a recent small news item I couldn't post because of the outage, Dr. Park speaking in Helsinki.

http://www.hip.fi/seminars/

Thursday 12 November 2015 at 14.15 in E207 (note place): Jaeyoung Park (Energy Matter Conversion Corporation, San Diego)
Polywell Fusion – Electric Fusion in a Magnetic Cusp
Abstract: Nuclear fusion power is considered the ultimate energy source because of its nearly inexhaustible supply of cheap fuels,
intrinsic safety, zero carbon emissions and lack of long-lived radioactive waste. In this talk, I will introduce the Polywell fusion concept that may offer a low cost and rapid development path to power the world economically and sustainably. As conceived by Dr. Robert Bussard at Energy Matter Conversion Corporation (EMC2) in 1985, the Polywell fusion concept combines electric fusion with magnetic cusp confinement. This allows the Polywell reactor to be small, stable, and highly efficient. Recently, EMC2 carried out an experiment that demonstrated dramatically improved high-energy electron confinement in a magnetic cusp system operating at beta (=plasma pressure/magnetic field pressure) near 1. This result has significant implications for cusp related schemes for producing controlled nuclear fusion power.
CHoff

choff
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Re: EMC2 news

Postby choff » Sat Oct 31, 2015 9:03 pm

There's been a recent small news item I couldn't post because of the outage, Dr. Park speaking in Helsinki.

http://www.hip.fi/seminars/

Thursday 12 November 2015 at 14.15 in E207 (note place): Jaeyoung Park (Energy Matter Conversion Corporation, San Diego)
Polywell Fusion – Electric Fusion in a Magnetic Cusp
Abstract: Nuclear fusion power is considered the ultimate energy source because of its nearly inexhaustible supply of cheap fuels,
intrinsic safety, zero carbon emissions and lack of long-lived radioactive waste. In this talk, I will introduce the Polywell fusion concept that may offer a low cost and rapid development path to power the world economically and sustainably. As conceived by Dr. Robert Bussard at Energy Matter Conversion Corporation (EMC2) in 1985, the Polywell fusion concept combines electric fusion with magnetic cusp confinement. This allows the Polywell reactor to be small, stable, and highly efficient. Recently, EMC2 carried out an experiment that demonstrated dramatically improved high-energy electron confinement in a magnetic cusp system operating at beta (=plasma pressure/magnetic field pressure) near 1. This result has significant implications for cusp related schemes for producing controlled nuclear fusion power.
CHoff

CherryPick
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Re: EMC2 news

Postby CherryPick » Sun Nov 01, 2015 8:22 am

Is anyone on this forum going to this seminar? I have work that time and can't take part. Of course Park's slides and video is highly appreciated.

choff wrote:There's been a recent small news item I couldn't post because of the outage, Dr. Park speaking in Helsinki.

http://www.hip.fi/seminars/

Thursday 12 November 2015 at 14.15 in E207 (note place): Jaeyoung Park (Energy Matter Conversion Corporation, San Diego)
Polywell Fusion – Electric Fusion in a Magnetic Cusp
Abstract: Nuclear fusion power is considered the ultimate energy source because of its nearly inexhaustible supply of cheap fuels,
intrinsic safety, zero carbon emissions and lack of long-lived radioactive waste. In this talk, I will introduce the Polywell fusion concept that may offer a low cost and rapid development path to power the world economically and sustainably. As conceived by Dr. Robert Bussard at Energy Matter Conversion Corporation (EMC2) in 1985, the Polywell fusion concept combines electric fusion with magnetic cusp confinement. This allows the Polywell reactor to be small, stable, and highly efficient. Recently, EMC2 carried out an experiment that demonstrated dramatically improved high-energy electron confinement in a magnetic cusp system operating at beta (=plasma pressure/magnetic field pressure) near 1. This result has significant implications for cusp related schemes for producing controlled nuclear fusion power.
--------------------------------------------------------
CherryPick
Ph.D.
Computer Science, Physics, Applied Mathematics

D Tibbets
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Re: EMC2 news

Postby D Tibbets » Mon Nov 16, 2015 9:51 pm

This link has more information than I have seen before. It may be frpm US-Japan 2015 confrence, but I missd it.

http://iec.neep.wisc.edu/usjapan/16th_U ... lywell.pdf

It is linked through the above link given by choff.

http://newenergyandfuel.com/http:/newen ... rd-fusion/

I do not yet understand the significance of the cusp potential dropping to zero volts. Any update on the presentation?

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

happyjack27
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Re: EMC2 news

Postby happyjack27 » Sun Nov 22, 2015 4:18 pm

I do not yet understand the significance of the cusp potential dropping to zero volts.



Referring, I presume, to: "Plasma potential at the corner cusp drops to 0V with increasing plasma density
-> Grid biasing does not look promising for Potential Well formation" from the .pdf. http://iec.neep.wisc.edu/usjapan/16th_U ... lywell.pdf

My interpretation is that the point cusps remain a large loss channel for ions. i think he's saying the potential well for the ions appears to have "valleys" that are just low enough for ions can escape out the cusps. Which limits their confinement time.

ions can probably find plenty of electrons at the cusps to neutralize their mutual repulsion, thus they can continue to ride in that thin line they need to to make it through the peephole.

i think he's worried about how much the magrid voltage can really help to recirculate these ions. though yeah he's definitely not very precise in the slide. 0 volts where, spatially? with reference to what? what's the voltage _gradient_ there? etc. not enough info...

Tom Ligon
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Re: EMC2 news

Postby Tom Ligon » Mon Nov 23, 2015 1:12 am

What I got out of Park's analysis is that the idea of using the Polywell magnet structure as a grid was kind of a red herring, i.e. the magrid is not the best way to run a Polywell. The magnetic structure is very effective at holding plasma at high beta conditions, but no e-gun using the magrid as the extraction and accelerating device is going to get the energy needed into the machine.

I, of course, am one of the principal propagators of the magrid idea ... just quoting Dr. Bussard without doing a full analysis myself, but I think a lot of us brought up questions about it.

Recalling what we were attempting back in Manassas Park with dispenser cathodes and extractor grids built right over the cathode surfaces, that's probably about right. E-guns strictly obey space charge limitations, especially close to the cathode, and attempting to accelerate electrons with a charge at a distance you inherently limit the current they can produce.

Plus, if the magnets are properly insulated by the magnetic field, they can't pass enough current to make the device work. The cusp loss points on the old style Polywells apparently let them work to a degree, but it is likely that eliminating the nubs on WB8 also reduced the ability of the magnets to act as an accelerating grid.

What WB-Mini did was finally figure out how much current and energy it takes to get a real wiffleball and the diamagnetic condition needed for high beta. Apparently, that means you need real e-guns and not the magrid approach.

rjaypeters
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Re: EMC2 news

Postby rjaypeters » Mon Nov 23, 2015 1:46 am

I don't know if this is apropos:

Discovery Could Enable Portable Particle Accelerators

Innovation could hold the key to ultra-compact machines useful for materials science and medical imaging

"A new discovery by physicists could hold the key to the construction of inexpensive, broadly useful, and portable particle accelerators in the very near future. The team has accelerated electron beams to nearly the speed of light using record-low laser energies, thus relieving a major engineering bottleneck in the development of compact particle accelerators."

http://www.sciencedaily.com/releases/20 ... 143543.htm

We do want to efficiently inject electrons, yes?
"Aqaba! By Land!" T. E. Lawrence

R. Peters

ladajo
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Re: EMC2 news

Postby ladajo » Mon Nov 23, 2015 2:11 pm

That is interesting also given Park's interest in possibly using lasers to excite the plasma.
The development of atomic power, though it could confer unimaginable blessings on mankind, is something that is dreaded by the owners of coal mines and oil wells. (Hazlitt)

What I want to do is to look up C. . . . I call him the Forgotten Man. (Sumner)

Solo
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Re: EMC2 news

Postby Solo » Mon Nov 23, 2015 5:38 pm

@Dan Tibbets: Nice find! There's more info in that presentation than I saw at Dr. Park's talk here at the UW last year. I'm glad they have done more work to shore up the interpretation of the X-ray blips, but I am still skeptical. For instance, if you look at the purple trace in the figure on slide 32, you see that the post-high-beta phase has at least as much x-ray emission as the earlier pulse. They may be injecting more impurities than they realize.

The confinement time of the cold plasma is something like 180us according to the decay time from their interferometer. That seems reasonable for a cusp device. Suppose you have the 10 cm radius sphere he's talking about in slide 24. Then working backwards from the assumption that Volume * dn/dt =n * v_th * A_loss, you get 13 mm^2 for the total loss area. Going the other way, if you assume 10eV ions and electrons, the loss area per cusp is given by A_gyro=pi*(Diam/2)**2, with Diam=4*rho_hybrid (from linear cusp width estimates), then you get A_gyro =0.4 mm^2, so for 12 cusps you get
5 mm^2, which is within uncertainties of the 13 mm^2 loss area from the decay rate. So I would say that this experiment supports the traditional scaling law. The trouble with that scaling law is that confinement is inversely proportional to the thermal velocity, so you get hosed when you want to go to reactor conditions.

@ Tom Ligon: Yes, I think your interpretation is correct: if the electron emitters are at ground, and the coils are biased, the cusp potential needs to follow the coil potential in order to draw electrons from the emitters. However, it looks like the presence of the plasma screens the coil potential at the cusp (unsurprising). So yes, they need to bias the emitters and use an extracting grid to generate an electron beam.

@R.J. Peters: the accelerators in the press release you mention are targeting MeV or greater energies, which is overkill for the polywell. also, they are talking about short-pulses sources, and their idea of efficiency is pretty low (1% is better than the state-of-the-art for them I think).

Tom Ligon
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Re: EMC2 news

Postby Tom Ligon » Mon Nov 23, 2015 5:54 pm

Solo,

I've described a discovery (I'd personally call it an accident) with PXL-1 here on multiple occasions. Magnets outside the stainless steel box. Corners should have leaked like a sieve. But I apparently coaxed it into holding electrons at high energy on the order of a second, and the energy released when the magnets turned off was stupendous. The only way I could account for the magnetic effects seen in the coils was a sudden release of high energy electrons to the walls.

I've heard of similar accidents with electron storage rings.

The only way I could think to plug up the cusp holes was cold electrons getting pushed into them and effectively shielding the cusp holes. I'm not sure the analysis is correct, but my intuition said that the trap would hold cold electrons better than hot electrons, and topologically, with a high negative charge in the center of the machine and with the magnetic field protruding into the device elsewhere, it made sense that cold electrons, no doubt taking a fair amount of plasma with them, would slide into the cusps. The tendency of these machines is to stay quasi-neutral.


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