Talk-Polywell.org

Posted: **Wed Dec 09, 2009 9:17 pm**

KitemanSA wrote:
Art Carlson wrote:
KitemanSA wrote: Heck yes! Then I would want you to say, "thank God the Polywell isn't a shpherical magnet confinement system for electrons!"

The confinement system is the positive grid. The magnets just protect the grid; oh, and improve the grid confinement a thousand(?) fold.
That may what you'd want me to say, but what I'm gonna say is that your understanding of how a polywell works is sure different from everyone else's here.
Maybe that is what has been causing all the confusion around here. My description is as simple and accurate as can be, I think, though you may be yet again shifting the discussion back to the ions. My statement is in reference to the electrons which were the topic of discussion when I made the statement. The MaGrid contains the electrons as I stated above. The electrons create a potential well that contain the ions. Ok?

Would it have been more acceptable to you if I had said "The confinement system for the electrons is the positive grid"?

Sorry, but the party line is that the electrons are magnetically confined. At least that would work, albeit poorly. What you describe will not work at all.

Posted: **Wed Dec 09, 2009 9:49 pm**

KitemanSA wrote:Would it have been more acceptable to you if I had said "The confinement system for the electrons is the positive grid"?

urrr... so now you're getting back towards the Meeks setup with a positive grid to 'confine' electrons that then confines positive ions? (The thing that never worked?!)

Hey, maybe the way that a fusor works is this; the negative inner electrode confines ions. The ions confine electrons. And the electrons confine ions so that electrons are confined that confine fast ions.

....it's beginning to sound alot like a neutral plasma to me!!!!.... (and fast ions thermalise in a neutral plasma)

Posted: **Wed Dec 09, 2009 10:49 pm**

Art Carlson wrote:
alexjrgreen wrote:A slowly outward moving ion at the edge of the wiffleball sees only a point negative charge at the centre of the well, decelerates and accelerates back towards it.
If you had done the homework assignment, you would know that it is not sufficient to consider only the interaction of the ions with the spherically symmetric component of the electron distribution. The contribution of the electrons in the cusp fan is huge.

Art, you're losing yourself here.

The electrons leave the central cusps in jets, not fans, because of the magnetic field and they're accelerating away so the jet density is much lower than that in the wiffleball. You can see this on the WB7 photo.

Once the electrons are past the magrid they slow down and there's an appreciable electron density there, but an ion at the edge of the wiffleball can't see that.

Posted: **Wed Dec 09, 2009 11:33 pm**

chrismb wrote:
KitemanSA wrote:Would it have been more acceptable to you if I had said "The confinement system for the electrons is the positive grid"?
urrr... so now you're getting back towards the Meeks setup with a positive grid to 'confine' electrons that then confines positive ions? (The thing that never worked?!)

Hey, maybe the way that a fusor works is this; the negative inner electrode confines ions. The ions confine electrons. And the electrons confine ions so that electrons are confined that confine fast ions.

....it's beginning to sound a lot like a neutral plasma to me!!!!.... (and fast ions thermalise in a neutral plasma)

I think you mean the Elmore/Tuck/Watson machine , not the Meeks machine. The rest of your post is circular. I think a ETW machine has to maintain an electron excess inside the positive grid through electron gun injection, otherwise there would be no potential well to contain the ions. Even if the positive grid was magnetically shielded, a lot of upscattered ions would escape. But, in the Polywell this magnetically shielded grid is arranged so that there is also 'backup magnetic containment' of the fuel ion population. This effect is considerable if a Wiffleball is assumed. According to R. Nebel, even very energetic alphas are contained in this fashion for ~ 1000 passes.
Recirculation can be considered as a magnetically shielded ETW machine. The internal electron magnetic confinement can be considered a magnetic mirror machine. A poor confinement machine, unless you accept the Wiffleball effect (~ 1000x gain). The Wiffleball electron confinement is 'moderate' in efficiency, but not good enough for breakeven. Recirculation is a poor confinement machine on its own, with only ~ 90% efficiency (9/10 electrons recovered), Or another way of looking at it is that it only confines cusp electrons for 10 passes. Yet another way of looking at it is that it is a poor confinement effect by itself, but it selectively allows the escape of the top 10 of electrons that have too much energy. The Wiffleball magnetic containment confines for ~10,000 electron passes (in WB6, I'm not sure how that will scale). The key point is that both methods compliment each other. I speculate that recirculation also has a benefit by slowing thermalization of the electrons with minimal cost. The electrons that do escape recirculation are upscattered, so allowing them to escape is good, while the pos magrid recovers a significant portion of the otherwise lost energy.

My estimate of the electron confinement time in WB6 was ~ 2.5 milliseconds. This is similar to a couple of references I found for toroidal devices of ~0.5 to 2 ms.

http://jjap.ipap.jp/link?JJAP/17/903/

http://adsabs.harvard.edu/abs/1977plsc.conf.....R

Newer toroidal machines may have improved on this, and I don't know whether these numbers incorperate expected instabilities or not. In any case the confinement time for electrons is probably within an order of magnitude of Tokamaks. The advantage is that in Tokamaks this confinement time applies to all charged particles. Also, if the confinement time per electron is similar, the total power needed to maintain the total number of electrons is much less in a Polywell due to it's smaller size. Even the increased density of electrons in the Polywell and the associated power needed to maintain this increased density is apparently offset by the volume differences. If there is any central concentration of electrons in the Polywell, the volume considerations increases the Polywell's advantage over the Tokamak's thermal electron distribution in the plasma torus even more. In the Polywell the ion containment is significantly greater (at least it is claimed to be). This along with the claimed nonmaxwellian conditions results in the claimed ~ 60,000 or more gain in power density. The details that determine how accurate the claims are is yet to be confirmed by AVIABLE data. Lacking this allows for considerable skepticism, but not derision.

Dan Tibbets

Posted: **Wed Dec 09, 2009 11:45 pm**

Yes. I am corrected. The ETW device is what I meant to reference. I will edit prior post.

I am curious to deduce why you think my arguments are circular, yet you do not see such fault in your own. Always with the present tense presuming the Wiffleball to be a clear and present effect. It is sooo reliant on this concept, yet the evidence for it is........??

OK, I guess that makes the argument that uses the 'Wiffleball' as a means for debate to be more spiral than circular; as per the newly-filed flight plan of a one-winged plane, just as some mid-flight event modifies its two-winged take-off configuration.

Posted: **Thu Dec 10, 2009 12:32 am**

chrismb wrote:OK, I guess that makes the argument that uses the 'Wiffleball' as a means for debate to be more spiral than circular; as per the newly-filed flight plan of a one-winged plane, just as some mid-flight event modifies its two-winged take-off configuration.

There's nothing hypothetical about the wiffleball. You can see one here: WB7. It's a magnetic quasi-sphere with holes in it, that incompletely confines electrons (as you can see from the helium fluorescence).

In a polywell, the doughnut shaped configuration of the magrid permits the recirculation of a majority of the electrons lost by the wiffleball (as you can also see from the helium fluorescence).

Posted: **Thu Dec 10, 2009 12:44 am**

chrismb wrote:Yes. I am corrected. The ETW device is what I meant to reference. I will edit prior post.

I am curious to deduce why you think my arguments are circular, yet you do not see such fault in your own. Always with the present tense presuming the Wiffleball to be a clear and present effect. It is sooo reliant on this concept, yet the evidence for it is........??

OK, I guess that makes the argument that uses the 'Wiffleball' as a means for debate to be more spiral than circular; as per the newly-filed flight plan of a one-winged plane, just as some mid-flight event modifies its two-winged take-off configuration.

At least my intrepratation of your post was that you were implying that the Polywell or similar approach was essentailly a silly perpetual motion like concept. But, just like in a Tokamak, spheromak, RFP, etc. there are real input and output concerns, and how they interplay determines the feasability of the system. There also seems to be a devide between assumptions and little willingness to compromise or explore methods to bridge the gap. Perhaps (or mabey even probably) I am contaminated by Bussard's view that those not firmly grounded in vacuum tube technology are at a disadvantage in addressing electrostatic and IEC issues. Or perhaps it is the other way around. Irregardless, there seems to be a schism in attitudes and methods.

Dan Tibbets

Posted: **Thu Dec 10, 2009 1:28 am**

What he seems to want you to do is to not make any sort of argument that assumes the polywell works.

Posted: **Thu Dec 10, 2009 1:31 am**

Art Carlson wrote:
KitemanSA wrote:
Art Carlson wrote: That may what you'd want me to say, but what I'm gonna say is that your understanding of how a polywell works is sure different from everyone else's here.
...Would it have been more acceptable to you if I had said "The confinement system for the electrons is the positive grid"?
Sorry, but the party line is that the electrons are magnetically confined. At least that would work, albeit poorly. What you describe will not work at all.

Wha?? The electrons are attracted in by the magnetically protected positive grid, within which they bounce around for a while (that was the "improved the grid confinement by a thousand(?) fold" part) LEAK OUT the cusps and are RECIRCULATED (confined!) by the positive charge on the MaGrid. Standard explanation. When do you think you changed it?

Posted: **Thu Dec 10, 2009 1:36 am**

chrismb wrote:
KitemanSA wrote:Would it have been more acceptable to you if I had said "The confinement system for the electrons is the positive grid"?
urrr... so now you're getting back towards the Meeks {{is this the same as the Elmore Tuck Watson? <KitemanSA> Oops, I now see your subsequent post acknowledging the mix-up }} setup with a positive grid to 'confine' electrons that then confines positive ions? (The thing that never worked?!) {{(No magnetic protection on that one by the way. <KitemanSA>}}

Posted: **Thu Dec 10, 2009 8:04 am**

Betruger wrote:What he seems to want you to do is to not make any sort of argument that assumes the polywell works.

Is this comment to highlight my correct application of "the scientific method" or to condemn it?

That principle permits you to;
a) presume things which are fully evidenced and have entered into mainstream assumption (*notwithstanding the inclusion of caveats wrt item c, the balance of probabilities),
b) assume a thing neither works, nor does not work, but to allow the evident facts to tell you,
c) assume all possibilities and compare the probabilities of all of them, on balance, with caveats to cover outside possibilities.

"Occam's razor" is not a scientific method but it might aid efficiency as you progress investigations into c, though it also carries risks of being mislead to the wrong conclusions. The inverse of Occam's razor [also not a scientific method] is what I might now consider calling "Nebel's octuple-bladed compound multi-powered manual-guidance-piloted self-exciting razor", if there is no other term for it, which seems to focus the investigation on a very complex interpretation where a simple one may suffice.

In the case of your comment [presuming it is a condemnation] on the wiffleball, it either falls outside these means to progress the scientific method, or I'm missing some.

Posted: **Thu Dec 10, 2009 8:08 am**

alexjrgreen wrote: There's nothing hypothetical about the wiffleball. You can see one here: WB7. It's a magnetic quasi-sphere with holes in it, that incompletely confines electrons (as you can see from the helium fluorescence).

Really! I didn't know you can see electrons, except where they are recombining and I thought the wiffleball was good at avoiding recombination.

Can you direct me to the diagnostic analysis of this image? It looks like a gas discharge structure to me.

Posted: **Thu Dec 10, 2009 8:26 am**

chrismb wrote:
Betruger wrote:What he seems to want you to do is to not make any sort of argument that assumes the polywell works.
Is this comment to highlight my correct application of "the scientific method" or to condemn it?

It's to call it for what it is. Any post made on this forum will have you policing it with the same response everyone's heard ten times already, adding nothing new, if it dares work on the assumption that polywell works. I'm just curious how much crow you're ready to eat if it turns out to work. Or will you just find some excuse, then? How difficult is it for you to understand that people already know that it's an assumption, not a guarantee, that Polywell works. That when people brainstorm some spaceship based on a Polywell or Mach-Effect drive, it's not actually breaking or harming anything?

If there's a technical flaw in the reasoning downstream of the assumption that polywell or whatever other hypothetical works out, then that's fair game. But insisting that there's something wrong with a voluntary assumption that one step or other is taken for granted.. There's no use pointing out to him that he's taking it as working assumption. That's an explicit premise. Stifling that is no use.

Posted: **Thu Dec 10, 2009 8:46 am**

chrismb wrote:
alexjrgreen wrote: There's nothing hypothetical about the wiffleball. You can see one here: WB7. It's a magnetic quasi-sphere with holes in it, that incompletely confines electrons (as you can see from the helium fluorescence).
Really! I didn't know you can see electrons, except where they are recombining and I thought the wiffleball was good at avoiding recombination.

Can you direct me to the diagnostic analysis of this image? It looks like a gas discharge structure to me.

Pictured above is a test plasma inside WB7 using Helium

See The e/m of the Electron Apparatus - standard college level laboratory equipment.

The vacuum tube has a downward pointing electron gun in an evacuated bulb that has a little helium added so that the path of the electron in tube is visible. The helium gas added to the tube fluoresces when struck be the moving electrons and produce a bright, clear view of their circular path, Thus, the circular tracing of the electron path is undisturbed by the previously emitted electrons, contributing to a more accurate measurement.

Posted: **Thu Dec 10, 2009 8:52 am**

alexjrgreen wrote:The electrons leave the central cusps in jets, not fans, because of the magnetic field and they're accelerating away so the jet density is much lower than that in the wiffleball.

I usually talk of fans because I think the line cusps are more important than the point cusps, but the same point applies to the jet or beam of the point cusp.

Here's an extra assignment just for you: Given (a) mono-energetic electrons with 100 keV energy and radial velocity at the edge of the WB, and (b) 100 V potential difference between the edge of the WB and the maximum potential, what is the reduction factor of the electron density between the edge of the WB and the position of maximum potential?

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