Why people are so optimistical to Polywell?

[D Tibbets]

TIME,Time, time. The timing of events is entirely different in Tokamaks and Polywells. Yes, other than some advantage from less thermal spread in the ions (this may be quite significant- perhaps by an order of magnitude) the Polywell ions would have the same dwell time to fusion as a Tokamak, IF they were at the same density. BUT, they are not. The Polywell is claimed to operate at several orders of magnitude greater densities. This is an absolutely necessary characteristic and is dependent on claimed Wiffleball formation. This gives the ~ 60,000 x advantage that Dr Nebel claimed. Unsurprisingly dividing the confinement requirment estimates that I used, yeilds this ~ number. In a volume of plasma, where the fusion is made up by injection of new ions (steady state) then if the density is ~ 250 times higher the fusion rate will be ~ 60,000 times faster. It in a Tokamak the ion hangs around for 100 seconds befor having a likely chance of fusion, then in the comparable Polywell the ion would need to hang around ~100 s/ 60,000= ~ 2 milliseconds. In this respect the potential well has to hang on to the ions only for his long (at least in this example). I don't think any of this is tearably hard from a physics standpoint (the engineering can be a bitch) but the real question is how much energy has to be put into the machine to maintain these conditions. Even Rider, the protagonist, doesn't say it is impossible, but that it cannot be done in a net positive way.

Dan Tibbets

[ladajo]

InterNET reporters.

Ok, thanks. Are those people influential enough for moving forvard the projects?
Even Polywell with 7 millions budjet. I do not talk about ITER's multi-billions.

I wanted to follow up on this. Joseph, the short answer is yes, there are folks who watch this forum that are influential enough to carry polywell forward if need be. The key point is for now, there is no need.

[ladajo]

Also, I wanted to add that you seem to be stuck trying to relate polywell to a beam to beam typ system. It is more than that, as it acts in all 4 dimensions. This is where folks (IMHO) have a hard time making the leap. Those ideas that may apply in sinlge or two dimensions, do not apply so well in 3 and 4. Thus the annealing theory, the distribution theories for ions and e-, the continuing debate about thermalization and its mechanisms (which to our knowledge has not yet showed in the experiments), as well as scaling. It is all hard to model, and is hard to interpret in practice.
The main answer to your header for this thread by my thinking is that so far, we have no reason not to be optimistic(al) about polywell.
If it were easy, we would not call it an experiment. If we end it, we would call it a failed hypothesis. None of this has occrued yet.

[KitemanSA]

What does "Ions have not radial arrange velocity" mean?.

May be not arrange but coherent? Beams have not coherent radial velocity. "Coherent" or "arrange” in English?

Nope, still doesn't compute. Sorry.

Why do you equate thermal and radial energy?.

Is a radial chaotic energy in the beams not thermal?

What beams? Are we talking about your idea or Polywell? Polywell doesn't have "beams" per-se, just ions falling radially toward the center of the quasi-spherical well or climbing radially out. The "chaotic" motion is not radial but tangential. The radial motion is brought to ZERO by the well (except a small proportion that has up-scattered) while the "chaotic" (thermalized, TANGENTIAL) motion becomes Maxwellian at the cold edge. The ions then gain the well depth worth of kinetic energy as they fall RADIALLY back down the well. The cold Maxwellian distro is TIGHTER in energy distribution than the hot center. This is annealing.

If your definition of "quasi-neutral" requires the TOTAL neutralization in space, then either we are defining our spaces differently or you have a different definition than everyone here (I think)..

In Soviet physics plasma with equal densities of ions and electrons called quasi-neutral. "quasi" because in the various fields anisotropy occurs. Returning to your definition if you will not neutralized totally space charge you will not reach declared density 10^19-10^22. Another way is to use relativistic electrons and partial compensation of space charge or in the other words - non-neutral plasma (by my definition. And not only mine) http://nonneutral.pppl.gov/

Then it seems we ARE using different definitions here. The plasma in the Polywell has been called "quasi-neutral" by every scientist working on it as far as I can tell. THEIR definition seems to be ALMOST neutral, but not quite. It is understood by most of us that a slightly negative charge is maintained in order to maintain the well.

Again, it is important to remember that the slight imbalance is not a constant proportion but a constant absolute difference. If you need to inject 1E7 electrons into the MaGrid to create the well then the system will need 1E7 more electrons than ion (charges) to maintain the well. This allows the total ion count to be 1E22 and the electron count to be 1E22+1E7. This is so very close to neutral, wouldn't it permit of the very high plasma densities being discussed?

[93143]

A minor clarification: thermalization affects velocity spread in the radial direction as well as the tangential direction(s). Annealing should apply to both.

[Joseph Chikva]

Also, I wanted to add that you seem to be stuck trying to relate polywell to a beam to beam typ system. It is more than that, as it acts in all 4 dimensions. This is where folks (IMHO) have a hard time making the leap. Those ideas that may apply in sinlge or two dimensions, do not apply so well in 3 and 4.

Yes, I see at Polywell as on device where ions oscilate having maximum velocity in the core and changing direction at the edge. Also I see not 3 and 4 but at least 6 directions. Is not it correct?

Thus the annealing theory, the distribution theories for ions and e-, the continuing debate about thermalization and its mechanisms (which to our knowledge has not yet showed in the experiments), as well as scaling. It is all hard to model, and is hard to interpret in practice.

If you are not personaly involved in project, you have somewhere read about annealing. As I have understood, it is the certain mechanism, called to slow down thermalization. Where can I read explanation?
Thanks.

[Joseph Chikva]

A minor clarification: thermalization affects velocity spread in the radial direction as well as the tangential direction(s).

Yes, of course. But the cooling method with which I familiar allows dissipate only radial component. Then naturally via collisions the equilibrium occurs.

Annealing should apply to both.

What such new have thought up?

[Joseph Chikva]

What does "Ions have not radial arrange velocity" mean?.

May be not arrange but coherent? Beams have not coherent radial velocity. "Coherent" or "arrange” in English?

Nope, still doesn't compute. Sorry.

Why do you equate thermal and radial energy?.

Is a radial chaotic energy in the beams not thermal?

What beams? Are we talking about your idea or Polywell? Polywell doesn't have "beams" per-se, just ions falling radially toward the center of the quasi-spherical well or climbing radially out. The "chaotic" motion is not radial but tangential. The radial motion is brought to ZERO by the well (except a small proportion that has up-scattered) while the "chaotic" (thermalized, TANGENTIAL) motion becomes Maxwellian at the cold edge. The ions then gain the well depth worth of kinetic energy as they fall RADIALLY back down the well. The cold Maxwellian distro is TIGHTER in energy distribution than the hot center. This is annealing.

If your definition of "quasi-neutral" requires the TOTAL neutralization in space, then either we are defining our spaces differently or you have a different definition than everyone here (I think)..

In Soviet physics plasma with equal densities of ions and electrons called quasi-neutral. "quasi" because in the various fields anisotropy occurs. Returning to your definition if you will not neutralized totally space charge you will not reach declared density 10^19-10^22. Another way is to use relativistic electrons and partial compensation of space charge or in the other words - non-neutral plasma (by my definition. And not only mine) http://nonneutral.pppl.gov/

Then it seems we ARE using different definitions here. The plasma in the Polywell has been called "quasi-neutral" by every scientist working on it as far as I can tell. THEIR definition seems to be ALMOST neutral, but not quite. It is understood by most of us that a slightly negative charge is maintained in order to maintain the well.

Again, it is important to remember that the slight imbalance is not a constant proportion but a constant absolute difference. If you need to inject 1E7 electrons into the MaGrid to create the well then the system will need 1E7 more electrons than ion (charges) to maintain the well. This allows the total ion count to be 1E22 and the electron count to be 1E22+1E7. This is so very close to neutral, wouldn't it permit of the very high plasma densities being discussed?

First.
I know only two types of motion: coherent or having some non-zero arrange velicity and chaotic. It's all.

The difference between 10E22 and 10E22+10E7 is small. So, the plasma is quazi-neutral by my definition too.

Regarding Polywell I don't not only understand but do not know at all what is annealing consist of?
Your explanation about big cross section at the edge I understood as electron cooling (ion-electron interaction). Now you are saying that is certain ion-ion mechanism. I know only to way to cool coherently moving stream: to mix stream to another stream and pass some thermal energy, or radiation. I see that Polywell's invertors discovered a new phenomenon.

I need not your explanation. I need to do some reading on it from myself. But do not know where.

[Joseph Chikva]

The cold Maxwellian distro is TIGHTER in energy distribution than the hot center. This is annealing.

I have read just now.
Would you like to say that radial ion stream when it moves out of hot center will have lower temperature?

[Giorgio]

The cold Maxwellian distro is TIGHTER in energy distribution than the hot center. This is annealing.

I have read just now.
Would you like to say that radial ion stream when it moves out of hot center will have lower temperature?

From your last few posts is clear that there are issues due to language barrier, especially in understanding how the polywell "should" work.
Give a look to this, it might help you to clarify some points:
http://thepolywellblog.blogspot.com/201 ... chive.html

[Joseph Chikva]

The cold Maxwellian distro is TIGHTER in energy distribution than the hot center. This is annealing.

I have read just now.
Would you like to say that radial ion stream when it moves out of hot center will have lower temperature?

From your last few posts is clear that there are issues due to language barrier, especially in understanding how the polywell "should" work.
Give a look to this, it might help you to clarify some points:
http://thepolywellblog.blogspot.com/201 ... chive.html

Thanks.
Yes, language barrier is my big problem.
But I see a bigger problem here. Good speaking English people are discussing fusion forgetting that we can not avoid physics laws. They try to fight with thermalisation. But I know only two ways to do that:
to pass thermal energy to another substance
to radiate.

Now before I would not see a clear explanation of annealing I think that is like to Perpetuum Mobile. Sometimes is very difficult to prove that it is not viable.

[Giorgio]

But I see a bigger problem here. Good speaking English people are discussing fusion forgetting that we can not avoid physics laws.

What you seem not to grasp is that you cannot strictly apply those laws to the Polywell because it is based on a completely different idea.

They try to fight with thermalisation. But I know only two ways to do that:
to pass thermal energy to another substance
to radiate.

Now before I would not see a clear explanation of annealing I think that is like to Perpetuum Mobile. Sometimes is very difficult to prove that it is not viable.

Read the papers and try to understand the way the polywell is expected to work, than you might understand what they are trying to do.
Again, NO ONE is sure if it will work or not, but the idea is not stupid.

[KitemanSA]

Joseph,
Here is a basic question for you.
Suppost you had a cold plasma where the ditribution of ion velocities was broader than the Maxwell-Boltzmann distribution:
would the laws of physics require the distribution to tighten up until the M-B distribution was reached?

[KitemanSA]

Yes, language barrier is my big problem.
But I see a bigger problem here. Good speaking English people are discussing fusion forgetting that we can not avoid physics laws. They try to fight with thermalisation. But I know only two ways {emphasis added} to do that:
to pass thermal energy to another substance
to radiate.

And now you have heard of a hypothetical third method. Annealing.
Both the methods you mention are lossy methods. They reduce the energy of the plasma. They "cool" the plasma. That is not what annealing "does"... is supposed to do... whatever.
Try to understand the hypothesized process rather than just declaring based on your personal knowledge (which MAY be limited) that it cannot be. A number of people here who understand the laws of physics can find no show-stoppers in the hypothesized process. I don't know of ANYONE who is CONVINCED that it exists, nor should they be until the data are in.
Understand the hypothetical process and await data; grasshopper.
(The term "grasshopper is a cultural reference - see :Kung Fu (TV Series) in wikipedia for details if needed)

[chrismb]

Joseph,
Here is a basic question for you.
Suppost you had a cold plasma where the ditribution of ion velocities was broader than the Maxwell-Boltzmann distribution:
would the laws of physics require the distribution to tighten up until the M-B distribution was reached?

yes it would. ok i'm curious now; what's your point?