Actual Polywell News!

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

Moderators: tonybarry, MSimon

chrismb
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Re: Actual Polywell News!

Post by chrismb »

DeltaV wrote:Seven wolftrons trapping a moosion:
A muon can catch two heavier deuteron nucleii, but they are still within an order of magnitude, and are going about the same, slow, speed.

A wolf catching a moose that is only three times as heavy as it, and running at the same speed, is one thing. An electron trying to catch a deuteron 3600 times heavier than it flying by at several million m/s is a different story.

Even with 35 times the Brillouin limit (not even stopping to question if a Polywell has remotely the same topology of fields as a Penning trap), the mass differential is still a couple of oom, and the speed differential is 'very non-zero'.

chrismb
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Re: Actual Polywell News!

Post by chrismb »

ladajo wrote:I guess we will agree to disagree then.
Sounds more like believing what you choose to believe, rather than agreeing or disagreeing.

Which statement is it that you disagree with, and why?

emc3
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Re: Actual Polywell News!

Post by emc3 »

Are these Australia gents better than US? I mean, USA Polywell experts?

We learned a lot from them, not from our secret EMC2.

Is EMC2 still there? so sad, can not find it anywhere.

DeltaV
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Re: Actual Polywell News!

Post by DeltaV »

chrismb wrote:An electron trying to catch a deuteron 3600 times heavier than it flying by at several million m/s is a different story.
The electrons in a Polywell may be trying to catch ions, but that's not their real job.

Their real job is to, en masse, diamagnetically expel the magnetic field and thus pull tight the drawstrings of the Wiffleball bag, trapping themselves like patrons of a crowded theater with too few exits, where someone has yelled "Fire!". The trapped electrons essentially become a superconductor which must expel B field lines.

It is the centroid of the confined electrons that serves as the focus for the spherically-convergent ions.

Nothing about Polywell requires that individual electrons, small numbers of electrons or even all of the electrons "trap" ions, beyond simply providing a central force to radially align the tracks of the infalling, accelerating ions, thus increasing the odds of ion collision and fusion.

ladajo
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Re: Actual Polywell News!

Post by ladajo »

chrismb wrote:
ladajo wrote:I guess we will agree to disagree then.
Sounds more like believing what you choose to believe, rather than agreeing or disagreeing.

Which statement is it that you disagree with, and why?
I believe you underestimate the aggregate effect of the electron cloud producing the virtual cathode.

Your argument is essentially there is no negative potential well. I find this to be completely ridiculous.

If there is a negative well, and there is sufficient relative volume around it to support (+) motion, there will be a 'containment effect' for the (+)s. A tiny bit of force goes a long way given persistance and time.

You base your argument that publically available data does not represent enough proof of "Fusion" produced neutrons due to electron well attracted ions.

I argue that there is enough information. Especially when you consider that fusors work on the same principle, only they do not use the "virtual" cathode concept. They use metal.

Show me your numbers that you can not attract enough fuel ions to have a fusion event with a 15KV electron well using what we publically know about (e-) density in the polywell. You say Brillion limit, I say show me.

This is an electrostatic confinement, it is not one (e-) trying to "catch" a (+). We have run numbers plenty of times regarding (e-) density and well depth. The point of Poylwell working is that (e-) and (+) do not recombine. Little missile, big sky theory and all.
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)

Joseph Chikva
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Re: Actual Polywell News!

Post by Joseph Chikva »

ladajo wrote:
chrismb wrote:
ladajo wrote:I guess we will agree to disagree then.
Sounds more like believing what you choose to believe, rather than agreeing or disagreeing.

Which statement is it that you disagree with, and why?
I believe you underestimate the aggregate effect of the electron cloud producing the virtual cathode.
You are right here. As clot of electrons really can produce potential (electrostatic) field very similar to gravitational field thus converting itself as a certain well (potential well) for ions.
For this purpose that clot should have enough density.
And despite your statement there is not any evidence that virtual cathode in Polywell has enough density. At least I could not find such evidence.
Here people including you believe that more powerful electron gun will produce well the depth of which will be proportional to electron current. But namely that is a big mistake.
Here very respectable by me Mr. Chrisb mentioned Brillion limit. Ask him what he meant.
Very interesting is his explanation. As I am sure that he once again mixes unmixable things in one salad.

choff
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Location: Vancouver, Canada

Re: Actual Polywell News!

Post by choff »

If Wolftrons and Moosions are a poor analogy how about Elephantrons and Army Antatrons, or Cowatrons and Black Flyatrons.
CHoff

D Tibbets
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Re: Actual Polywell News!

Post by D Tibbets »

...
Here people including you believe that more powerful electron gun will produce well the depth of which will be proportional to electron current. But namely that is a big mistake.
....
I won't argue about you other points, except to say that potential well formation has a lot of literature. Proceed through the Japan - US IEC conferences/ presentations as a starting source.

Your point about more powerful E- guns being the key being a fallacy may be pertinent, tough I doubt in the manner you perceive.

EMC2 tried increasing the power of the E guns with only a modest improvement in their potential well in WB5. The improvement was dissapointing because confinement issues were more important as they realized and which they applied to WB6.

Certainly increasing the E- guns raw power will increase the well depth, but it is a non linear process. Increasing the electron current is the key. The current is the input divided by the output. With no electron containment the current is 1 if 1 Coulomb is injected and 1 Coulomb exits per unit of time. This is where recirculation, confinement, superconductivity, etc. terms become applicable. They all increase the current in the system with out necessarily increasing the input current. If confinemnt causes the electrons to flow from point a to point b and back in the system this circular current is as effective as single pass currents with correspondingly greater input.

WB4 had confinement allowing for ~ 10,000 passes. This means the internal current was multiplied 10,000 fold relative to the input current. WB6 reportedly improved on this ~ 10 fold, partially through improved recirculation. Now the internal circular current was multiplied ~ 100,000 times relative to the input current.
WB6 had ~ 45 amps of input electron current, so the internal current was actually ~ 4.5 million amps. This 100,000 amplification in the system current is considerable. It would be challenging to increase the input current to anything approaching this even if you ignored the Q. Using Watts, the input current of 45 amps accelerated through 12,000 volts resulted in input power of ~ 500,000 Watts. Without any confinement / recirculation the necessary input power would have been ~ 50 billion Watts. So, it is safe to say that a lot of power was required to establish and maintain the potential well. Another way to say it is that only 500,000 Watts was required to establish the well, but only for a few microseconds at most. The confinement allows for this input to maintain the well for many milliseconds. This is equivalent to a superconductor as someone recently pointed out in another thread. A current flow is set up with power input, but thereafter it is maintained by the circular current without losses, and therefor no additional input requirements. The Polywell is not perfect like a superconductor so some input requirements are needed but they are (hopefully) modest and tolerable. Also, as there is some less efficiency as the Wiffleball is forming you need some minimal power level to ramp things up. You cannot trickle in power to establish the conditions. That is why EMC2 used high voltage capacitors to generate the 500,000 Watts of input power. They could produce plenty of electrons from batteries, but the accelerating voltage maintenance necessary could not be matched by their modest power supplies.

Polywell power input is supposed to scale B^0.25 * radius ^2. Multiply that by any increased voltage (like 120KV instead of 12 KV) and the need for robust power supplies/ E-guns becomes apparent.
A 3 meter and 10 Tesla machine might require 500KW * 4*100* 10 = ~ 2 billion watts of input power. This assumes confinement cannot be improved. Any small improvement in electron containment has a large impact. Note that with the scaling the fusion output in this machine would be ~ 0.001 W *100,000,000 *1000 * 100= 10 billion Watts. Profitable fusion is possible if the numbers are accepted. This also illustrates that anything that can improve on the input side (confinement efficiency and / or injection efficiency) leads to large benefits where size, cost, etc. issues are considered.

I don't know what the efficiency of the electrons emitted from the car headlight filaments getting into WB6 was. I don' know how much improvement could be made, but this is another area where any improvement could also be tremendously important to the final power requirements. I can see where it would be of prime concern to researchers who are modeling the system.

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

Joseph Chikva
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Re: Actual Polywell News!

Post by Joseph Chikva »

D Tibbets wrote:I won't argue about you other points, except to say that potential well formation has a lot of literature. Proceed through the Japan - US IEC conferences/ presentations as a starting source.

Your point about more powerful E- guns being the key being a fallacy may be pertinent, tough I doubt in the manner you perceive.

EMC2 tried increasing the power of the E guns with only a modest improvement in their potential well in WB5. The improvement was dissapointing because confinement issues were more important as they realized and which they applied to WB6.

Certainly increasing the E- guns raw power will increase the well depth, but it is a non linear process.
Nobody except Mr. Chris argues about potential well formation that capable to confine some ions. When he speaks about "very non-zero speed of ions and comparable speed of electrons". I would remind him that even stationary black hole (that is example of gravitational potential well) capable to "catch" even photons moving at 3E8 m/s.

But namely confinement issues (mistake is the statement that convex field allow formation of free of instabilities plasma) and non-linearity of dependenth of electron gun's current and depth of potential well will not provide you your desired scaling law.
Be noted that depth potential well is very dependent on level of electron cloud neutralization and partly neutralized cloud has lower depth.
So, your statement 3 m Polywell equipped with 10 T magnets would produce ???? MW power is a mistake.
You can quote me many sources about potential well formation but you cannot give me even one reliable source proving your desired scaling law.
And explanation of Nebel that scaling was not observed in Polywell only because of degassing is very weak. I am sure that reasons are much more than one.

Admit at last that Polywell did not show any scaling law ever.

Robthebob
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Re: Actual Polywell News!

Post by Robthebob »

I'm pretty sure polywells always reach input output equilibrium, perhaps at time scales we dont not care about. And at such equilibrium, whatever amount of wolftrons you throw into the system is equal to whatever amount of wolftrons losses. This has to be true or else the well will keep growing.

So what we're interested in is the well depth at input/output equilibrium given a set of parameters. For every given B field config, strength, machine config, etc there's a quality of how well these parameters can confine wolftrons, and you add wolftron beam into the mix, for whatever level of wolftron beam you throw into the system, there is a corresponding well depth.

So Chrismb brought up the issue of can wolftrons trap moosions on the micro-scale. The answer is no, they cant, because their energy level difference is too great. But that's precisely the design, they leave each other alone. In the hand waving paper ( "The Advent of Clean Nuclear Fusion: Super-performance Space Power and Propulsion"), Bussard went in great hand waving detail (this might be an oxymoron) to say that the wolftrons and moosions leave each other alone, at like all regions of the machine. If they didnt, shit would thermalize, that's bad jojo.

On the global scale tho, the wolftronic static potential does trap the moosions, that's how the machine is designed to work.

PS: I wrote a summery of stellarator work, and yes there's sims and experimental results to back the claims that having 3D shaping coils would make tok current instability problems go away. They have to deal with current at donut machine high beta anyways because of bootstrap current, and they do deal with it. Why ITER doesnt just have 3D coils to make all their control issues go away... I dont know.

(Just to say, I dont think Bussard knew WB effect would happen until like 2 or 3 WBs into the program, I could be wrong. If I'm right, then that's some kind of luck he had at discovering what diamagnetic effect would have on a concave (towards the center) B field. We're pretty lucky.)
Throwing my life away for this whole Fusion mess.

Joseph Chikva
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Re: Actual Polywell News!

Post by Joseph Chikva »

Robthebob wrote:I wrote a summery of stellarator work, and yes there's sims and experimental results to back the claims that having 3D shaping coils would make tok current instability problems go away.
Wrong. Real experiments showed that toks are more stable. After which stellarator C4 or C5 (I can be mistaken in number) in USA was converted in TOKAMAK. And from that moment USA involved in TOKAMAK development refusing stellarators.
The last actual Stellarator is Large Helical Device in Japan and that today is living its last days. And maybe even hours.
Robthebob wrote:They have to deal with current at donut machine high beta anyways because of bootstrap current, and they do deal with it.
Please define the term "bootstrap current" and please please inform in which generation of stellarator bootstrap current was observed.
Thanks in advance.

Robthebob
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Re: Actual Polywell News!

Post by Robthebob »

bro, you gotta be kidding me, boots strap current is current generated in "high beta" donut machines due to sufficient pressure gradient. This has been observed and dealt with in the HSX. I dont know where you're getting your information from, but math dont lie, stellarators are by design way more stable (at least to current driven instabilities) than toks, because the effects of the 3D shaping coils increase the field bending energy, which is stabilizing. In Toks, this just doesnt exist.

The ratio between the vacuum rotational transform (due to only the coils) to the total rotational transform (due to current and coils) can be like 10%, and it will basically never be unstable. Yes, you read correctly, you put like a tiny 3D coil effect on a tok, and current driven instabilities just go away.

So you may ask, why dont they do it this way? Well, politics and also I guess tradition. It's a long story, but basically no one in US do much on stellarators. Toks are easier to build, cheaper, and more people study it, so people just do that. They were going to make a big machine at Princeton and they ran out money. But they're building the W7X, so we'll see, but that doesnt have any ohmic current in it though, which can be wise, because ohmic current confinement cant be steady state.

But all your awesome features of Toks can be in a stellarator, like H-mode, bootstrap current, ohmic current, all that. Like I used to think you may have a case, but you dont, cus I saw the math myself, I read the papers, stellarators are just more stable to current driven instabilities 100% of the time.
Throwing my life away for this whole Fusion mess.

paperburn1
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Re: Actual Polywell News!

Post by paperburn1 »

BURN!
I am not a nuclear physicist, but play one on the internet.

chrismb
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Re: Actual Polywell News!

Post by chrismb »

ladajo wrote:Show me your numbers that you can not attract enough fuel ions to have a fusion event with a 15KV electron well using what we publically know about (e-) density in the polywell. You say Brillion limit, I say show me.
Consider Brillouin Limit:
Electron density/m^3, Ne = (e0)B^2 / 2(me) = 8.85E-12 x B^2 / 2(9.1E-31) = ~5E18 x B^2
Say, B=10 T
Ne = ~5E22

Consider an equivalent mass of deuterium being electrostatically confined by those electrons, Nd = Ne/3600 = 1.4E19

Consider the MFP for a 15 keV deuteron of ~s=5 millibarn (5E-31 m^2) fusion-cross section, in collision with Nd = 1.4E19/m^3:
MFP to a fusion event = 1/(s.Nd) = ~1.5E11 m

Consider the speed of a 15 keV deuteron = v = ~1.2E6 m/s [This is a very generous assumption - it is presuming the deuteron keeps up at fusible potential all the time, whereas in reality it is probably only fast enough to fuse for 10% of its reciprocating motion.]

Therefore, average time, t, for each deuteron to fuse = MFP/v = 1.5E11/1.2E6 m/s = ~120,000 s

Fusion power, Pf', for an average of a deuteron pair = ~5 MeV / 120000 = ~6E-18 W

Fusion power, Pf, per cubic meter of deuterons AT 15 keV (viz. the number of deuterons in a 'core' of a reaction space) = Pf = Pf' x Nd = 6E-18 W x (1.4E19/2) = ~47 W / m^3
(note – divide density by two as it takes two particles to fuse, so if all were counted, it'd be double-counting the probability of a fusion.)

So the question remaining is whether the electrical power required to maintain a 10T field across a space big enough to include within it a 1 m^3 sized reaction core, plus the power the electron injection system would need to maintain the electron population at that full Brillouin density enough to maintain a 15keV well depth, is likely to be less than the 47 W (thermal) output of this reactor?

Joseph Chikva
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Re: Actual Polywell News!

Post by Joseph Chikva »

Robthebob wrote:So you may ask, why dont they do it this way? Well, politics and also I guess tradition.
Polytics that forces so many Governments to spend billions for wrong program and to stop right?
"do math himself"
"100% stable all the time"
Hahaha-huhuhu-hehehe
And so on

Please provide also link of bootstrap current ever observed in stellarators.
Thanks

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