New patent application, similar to polywell.

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

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Torulf2
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Post by Torulf2 »

We actual had a tread abut this long time ago.
from that i remember this devise was smaller than polywell and have reverse polarity.

chrismb
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Post by chrismb »

KitemanSA wrote: Jeez, first he doesn't blow his trumpet enough, now he's trumpet blowing.
What are you talking about now? Is it impossible for you to be specific?

CosmicObserver
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Post by CosmicObserver »

What do you think of the 'active' recirculation, as opposed to a passive one? Can you really capture errant electrons/ions with minimal energy loss, and replace them with better behaved ones? The idea seems like a reasonable one, but my math/electronics skills are lacking.

c.o.

AlexK
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trumpet blowing

Post by AlexK »

Hello, I just filled our website with content. Hope it makes for interesting discussions. I'm interested in talking with a) technical experts who have comments and/or questions, b) people with money, and c) persons who might consider writing articles or producing other sorts of media.

Cheers,

Alex K.
FPGeneration

chrismb
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Post by chrismb »

...Tell us about your work with EMC2 and polywell!! ;)

I guess you have the world as an audience here on this forum, if you also found us discussing your work...so would you like to make any starting 'pitches' on the work with your device - I guess first off [if you have followed this site at all] maybe if you can tell us how much you can tell us!!

chrismb
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Post by chrismb »

Alex, 'fraid I can't pull any info up on the patent application references given on the website. Were these 'preliminary' unpublished applications?

The only one that I can find on USPTO or WIPO with your name on it is the one I've referenced here.

Well, either way, maybe we can dig straight down into the technical details - the principal question of any IEC system; can you explain how your systems recover the energy from non-fusing collisions and prevent thermalisation?

AlexK
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Post by AlexK »

Hi, thanks for the interest. Some of our patents have been flagged for secrecy, then "unflagged", but the patent office forgot to publish the application. We have been quite happy about this in the past few years.

Regarding thermalization:

Generally, once beam particles are above ~50 kV, thermalization happens at a rate that causes ion/energy losses which are smaller than the energy production rates due to fusion, unless there are instabilities (such as the 2-stream or Weibel). This is quite a general result.

Furthermore, in our MARBLE device, simulations show that ions wander slowly into unstable orbits (due to small angle Coulomb collisions) more often than they are "seriously kicked" out due to a large angle Coulomb collisions. This means that electrodes can be configured to "scrape off" ions as they get lost, so for example picture that electrode #x is of a slightly smaller diameter than electrode #x+1. Since electrode #x is at a potential not too different from electrode #x+1, the energy lost due to ion impact is only a fraction with which said ion was accelerated through the device.

Hope this makes sense.

chrismb
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Post by chrismb »

I hear what you are saying, but I'd like to see your maths because I don't believe you can achieve energy gain unless you avoid thermalisation and pull scattered ions back up to energy, however slowly and small the scattering angles involved. As the energy peels off the beam ions, they rapidly drop out of contention as viable fusible ions.

If it were that easy, then fast beams into gas targets would already be powering the electricity grid. Oliphant ran a 100keV deuteron beam into deuterium gas in 1934 and (fortunately for him sitting over the experiment, and all other amateurs running fusors!!) it didn't produce more neutrons than input power!!

AlexK
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Post by AlexK »

The Coulomb collision cross-section is about the same as the fusion cross-section at energies of ~100 keV. Two ions lost = 200 keV of energy, but two ions fusing = 20 MeV of energy, so fusion wins out. There are numerous beam based fusion designs that calculate precisely when and how net gain can be done, for example here's one:

M. Sherlock, S. J. Rose, and A. P. L. Robinson, “Prediction of Net Energy Gain in Deuterium-Beam Interactions with an Inertially Confined Plasma”, PRL 99, 255003 (2007)

chrismb
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Post by chrismb »

AlexK wrote:The Coulomb collision cross-section is about the same as the fusion cross-section at energies of ~100 keV.
For what scattering angle? 89.9deg!?

I'll beg to disagree with you here.

The 'average' Coulomb scattering cross-section never gets anywhere near a fusion cross-section. Most are small angle scatters of many 1,000s barns. e.g. a one degree scatter is around 10 to 20,000 barns at 0.1 MeV for deuterons and/or tritons. whilst the fusion cross-sections are 20 millibarn for DD and 2 barn for DT.

I'll admit that it doesn't look much if you consider each 1 deg scatter at 1MeV is a loss of only around 10eV per collision, but that has to also be summed up with losses from non-elastic collisions, ionisations and electron interactions. By the time you've had less than 10,000 collisions, your ion has lost all its energy for fusing but in the case of DD you'd need 20,000/0.02=100,000 such collisions for a fusion. 10 lots of 1MeV ion in, and 4MeV out. No gain. By that calc I grant you DT looks promising, but I trust you know its fusion resonance is at a point where ionisation losses are nearing a maximum and most ions will expire by inelastic collisions.

I would suggest that if you add in ionisation losses in a 'real' IEC system without particle energy recovery, then at 100keV you're looking at around one fusion event in 2,000,000 collisions, whilst 2,000,000 collisions would represent around 40MeV (i.e. they don't live that long whilst undergoing lossy, unrecovered collisions).

Do you have a 'free' link to the paper, you've referenced here, or other similar. I'd like to see how others have come to a different conclusion to mine.

DeltaV
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Re: New patent application, similar to polywell.

Post by DeltaV »

chrismb wrote:...and they have a, curently empty, URL;
http://www.fpgeneration.com/
No longer empty. MARBLE replaces MIX:
http://www.fpgeneration.com/marble/index.html

Image

Reminds me of the nested, conical-coil Polywell concepts discussed here in the the past, except it's a different concept using conical electrodes, not conical magnets. Cones opening inward instead of outward.

D Tibbets
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Post by D Tibbets »

chrismb wrote:
AlexK wrote:The Coulomb collision cross-section is about the same as the fusion cross-section at energies of ~100 keV.
For what scattering angle? 89.9deg!?

I'll beg to disagree with you here.

The 'average' Coulomb scattering cross-section never gets anywhere near a fusion cross-section. Most are small angle scatters of many 1,000s barns. e.g. a one degree scatter is around 10 to 20,000 barns at 0.1 MeV for deuterons and/or tritons. whilst the fusion cross-sections are 20 millibarn for DD and 2 barn for DT.

I'll admit that it doesn't look much if you consider each 1 deg scatter at 1MeV is a loss of only around 10eV per collision, but that has to also be summed up with losses from non-elastic collisions, ionisations and electron interactions. By the time you've had less than 10,000 collisions, your ion has lost all its energy for fusing but in the case of DD you'd need 20,000/0.02=100,000 such collisions for a fusion. 10 lots of 1MeV ion in, and 4MeV out. No gain. By that calc I grant you DT looks promising, but I trust you know its fusion resonance is at a point where ionisation losses are nearing a maximum and most ions will expire by inelastic collisions.

I would suggest that if you add in ionisation losses in a 'real' IEC system without particle energy recovery, then at 100keV you're looking at around one fusion event in 2,000,000 collisions, whilst 2,000,000 collisions would represent around 40MeV (i.e. they don't live that long whilst undergoing lossy, unrecovered collisions).

Do you have a 'free' link to the paper, you've referenced here, or other similar. I'd like to see how others have come to a different conclusion to mine.
While I'm not sure all of your small angle collisions add up as you say (probably in Rider's analysis it did, but Chacon's analysis was different), I'll accept it for this arguement. If you look at the previous post by AlexK, you'll see that he mentions what I think is a mechanism (where he is talking about electrode size) that mitigates the progressive loss mechanism, along with spherical geometries which I suspects modifies angular momentum losses that would apply to a tight columnar beam geometry.
You don't just consider the initial input energy, and the rate of energy loss through scattering, etc. You also have to consider energy recovery, recirculating effects, etc. I suspect here, as in the Polywell, these effects are what is important, not some claim of different physics.

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

Giorgio
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Post by Giorgio »

I think that if AlexK gives us some hints about their experimental results this issue could be cleared easily.

D Tibbets
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Post by D Tibbets »

Concerning small angle collisions verses large angle collisions. In another thread I argued with CB that they were equivalent (at least when considering a large sample of particles), CB did not think so, just as above. While it is not based on a deep understanding, my gut feeling is that whatever deflection angle you use to base your calculations on, the net effects are the same. If there is a difference, then you could carry the analysis to extremes. At small enough angle deflections even intergalactic plasmas would very quickly thermalize because as the deflection angle decreases the collision frequency would go up exponentially.

The relationship must be more linear, else the term Mean Free Path (MFP) as used for a basic predictor of plasma behavior would be meaningless. Mean Free Path, at least according to one plasma physics text, is the average distance a charged particle will travel before it has a 90% deflecting collision with another like particle.
Assume this distance is 1 meter. If you use 1 degree deflections, they will occur much more frequently, but the net effect must be the same. After 1 meter these more frequent collisions will result in the same net 90 degree deflection (on a statistical basis with many particles in the mix). With an individual particle, who knows what the result would be. One point when considering only one particle is that when it is deflected it may deviate plus one unit in angle either away from or towards the nominal line and do so in both the x and y planes. This results in a net statistical deviation for that individual particle that is 1/2, or 1/4th, or square root? less than simple 1 degree increase in deviant angle for each collision would suggest. This may or may not be the basis of all summed angle collision possibilities being predicted from one standard angle deflection, the MFP.

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

chrismb
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Post by chrismb »

Yes, there is equivalence between scatters of small angles. It's actually much simpler than how you've portrayed it:

If you were to take some small angle [sin(theta)=~theta] then for that angle there is a given cross-section and a given kinetic energy loss of the particle (to whatever it imparted its energy to - we are dealing here in this analysis only with fast particles into 'stationary' ones, viz. discounting upscattering). Now, if you were to then look at the energy loss for an angle half that size, you'd find that the energy lost is a quarter of that lost in the larger angle, but it has 4 times the cross section. This is because the scattering crosssection is a function of the square of the impact parameter, whereas the fractional loss of kinetic energy is a function of the square of the sine of half the deflection angle.

In other words; if you assume that all scatters within a fusion process are, for example, 1 degree and your hypothesis holds true under that assumption, then it is correct to infer that the hypothesis holds true for any other small deflection angle.

I shall give an example; let's say that the cs of a 1 deg scatter is 10,000 barns and the KE loss in that scatter is 20eV. Let's now compare that with a fusion cross section of probability 0.1 barn. This means that the 1 degree scatter is 100,000 times more likely than the fusion so to consider 'energy gain' we'd have to make sure that this 2,000,000eV lost is no more than the fusion energy gain minus all the other non-elastic losses. Now, after this analysis, we need do no more to evalate the elastic collisions because, for example, if we were to assume any other angle, the probability goes up in exact relation to the KE lost going down; say for 0.1deg scatters, the energy lost per collision is now 0.2eV but the cs of scatter is 1,000,000 barns. So there are 10,000,000 0.1 deg scatters per fusion, which is still 2,000,000eV lost in elastic collisions. See?... it makes no difference what the small angle of scatter actually is, so long as it is true for one particular small angle.

Oh yes, one more condition.... that 2MeV lost [in this example only] must either be considerably more than the original particle energy [else a population of such ions would 'die' before they get to fuse] or you need to pump them with energy somehow (e.g. a POPS-type scheme).

So you are right that all small scattering angles are 'equivalent'. The question is whether you can prove a given concept for a small angle.

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