Polywell In Europe Raising Funds

[alexjrgreen]

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?

Not sure why you chose those particular values. The reduction in density is clearly visible on the WB7 photo.

[Art Carlson]

...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?

Maybe we are (partly) using the language differently. I can't quote Bussard or Nebel readily, but Wikipedia uses language similar to mine: "the negative charges [are] confined to the inner region of the reactor by magnetic fields". If you want to say the electrons are confined by both magnetic fields (within the magrid) and electric fields (in the cusps), I can live with that.

This discussion started with the topological difference between a sphere and a torus when it comes to magnetic confinement. Both ions and electrons can be confined by a magnetic field everywhere parallel to the surface in a torus. In a sphere you have to have cusps somewhere. If you try to plug the cusps with electic fields, you have to decide whether to stop the ions or the electrons. You can't stop both. That is why the topology always plays a role.

[Art Carlson]

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?

Not sure why you chose those particular values. The reduction in density is clearly visible on the WB7 photo.

Choose any values you like. I guarantee you, someplace they won't fit together. As long as you only wave your hands, you will never see it. Calculate!

[alexjrgreen]

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?

Not sure why you chose those particular values. The reduction in density is clearly visible on the WB7 photo.

Choose any values you like. I guarantee you, someplace they won't fit together. As long as you only wave your hands, you will never see it. Calculate!

The WB7 photo is the only objective evidence I have of how a polywell works, so if your calculations say the picture is impossible then I'm going to tell you that your calculations are wrong.

The recirculation mechanism clearly works at WB7 scales. I need you to engage with that. The scale at which that mechanism breaks down may determine the maximum size of a polywell.

[Art Carlson]

The WB7 photo is the only objective evidence I have of how a polywell works, so if your calculations say the picture is impossible then I'm going to tell you that your calculations are wrong.

My calculations don't say the photo is impossible. They say your interpretation of the photo is wrong.

[alexjrgreen]

The WB7 photo is the only objective evidence I have of how a polywell works, so if your calculations say the picture is impossible then I'm going to tell you that your calculations are wrong.

My calculations don't say the photo is impossible. They say your interpretation of the photo is wrong.

Then you need to describe what you see, and we can go from there.

[Art Carlson]

The WB7 photo is the only objective evidence I have of how a polywell works, so if your calculations say the picture is impossible then I'm going to tell you that your calculations are wrong.

My calculations don't say the photo is impossible. They say your interpretation of the photo is wrong.

Then you need to describe what you see, and we can go from there.

Mostly I see an over-exposed photo with a lot of stray reflections, under conditions I know next to nothing about. But we can work with that.

I believe the claim was made that the light seen comes from the interaction of a low density of electrons with a low but nearly uniform density of helium. If you are only making claims about this vanishing density of diagnostic electrons, I guess I don't care and will leave you alone. Some of your statements might even be right.

If you are drawing additional conclusions from that about how a high density, quasi-neutral plasma would behave in a polywell, then I would have a considerable number of things to say. Are you? And if so, exactly claims would you like to make?

[alexjrgreen]

Mostly I see an over-exposed photo with a lot of stray reflections, under conditions I know next to nothing about. But we can work with that.

I believe the claim was made that the light seen comes from the interaction of a low density of electrons with a low but nearly uniform density of helium. If you are only making claims about this vanishing density of diagnostic electrons, I guess I don't care and will leave you alone. Some of your statements might even be right.

If you are drawing additional conclusions from that about how a high density, quasi-neutral plasma would behave in a polywell, then I would have a considerable number of things to say. Are you? And if so, exactly claims would you like to make?

I agree with the low but nearly uniform density of helium.

I don't agree with the low density of electrons, but you'll no doubt explain why you say that.

There will be some double ionisation of the helium, according to Tom Ligon.

If we can agree that the photo gives us a rough picture of the electron density before very many ions have been introduced, and that we can see what Dr Bussard described as electron recirculation, then we'll have made excellent progress.

[Art Carlson]

Mostly I see an over-exposed photo with a lot of stray reflections, under conditions I know next to nothing about. But we can work with that.

I believe the claim was made that the light seen comes from the interaction of a low density of electrons with a low but nearly uniform density of helium. If you are only making claims about this vanishing density of diagnostic electrons, I guess I don't care and will leave you alone. Some of your statements might even be right.

If you are drawing additional conclusions from that about how a high density, quasi-neutral plasma would behave in a polywell, then I would have a considerable number of things to say. Are you? And if so, exactly claims would you like to make?

I agree with the low but nearly uniform density of helium.

I don't agree with the low density of electrons, but you'll no doubt explain why you say that.

I am thinking low enough so that quasi-neutrality is not required. That is, the ratio of ion density to electron density is much less than 1. I am also thinking high enough that the electrons can produce a significant electric potential. I don't have strong reasons for saying this and stand to be corrected.

There will be some double ionisation of the helium, according to Tom Ligon.

If we can agree that the photo gives us a rough picture of the electron density before very many ions have been introduced, and that we can see what Dr Bussard described as electron recirculation, then we'll have made excellent progress.

I am unwilling to draw any firm conclusions at all from this photo, but we can take this as a working hypothesis.

[alexjrgreen]

I don't agree with the low density of electrons, but you'll no doubt explain why you say that.

I am thinking low enough so that quasi-neutrality is not required. That is, the ratio of ion density to electron density is much less than 1. I am also thinking high enough that the electrons can produce a significant electric potential. I don't have strong reasons for saying this and stand to be corrected.

Apart from the use of Helium, I have no reason to believe that this was anything other than a normal firing of WB7. I'm only expecting about half as many Helium atoms to be ionised as would be the case with Deuterium, perhaps less, so this would be a picture of what the electrons want to do.

If we can agree that the photo gives us a rough picture of the electron density before very many ions have been introduced, and that we can see what Dr Bussard described as electron recirculation, then we'll have made excellent progress.

I am unwilling to draw any firm conclusions at all from this photo, but we can take this as a working hypothesis.

Agreed.

[Art Carlson]

I don't agree with the low density of electrons, but you'll no doubt explain why you say that.

I am thinking low enough so that quasi-neutrality is not required. That is, the ratio of ion density to electron density is much less than 1. I am also thinking high enough that the electrons can produce a significant electric potential. I don't have strong reasons for saying this and stand to be corrected.

Apart from the use of Helium, I have no reason to believe that this was anything other than a normal firing of WB7. I'm only expecting about half as many Helium atoms to be ionised as would be the case with Deuterium, perhaps less, so this would be a picture of what the electrons want to do.

If we can agree that the photo gives us a rough picture of the electron density before very many ions have been introduced, and that we can see what Dr Bussard described as electron recirculation, then we'll have made excellent progress.

I am unwilling to draw any firm conclusions at all from this photo, but we can take this as a working hypothesis.

Agreed.

"Normal firing" and "before very many ions have been introduced" seem to contradict each other. What I keep harping on is that you will bleed ions and their attendant energy out the cusps at any reasonable density. Since we don't know whether the photo represents an operational shot or a diagnostic shot, we can't draw any conclusions concerning my analysis from the photo.

[alexjrgreen]

"Normal firing" and "before very many ions have been introduced" seem to contradict each other.

The ionization energy of Helium is nearly twice that of Deuterium. So, less ions. Plus, Helium will doubly ionise so even less ions, though some with double charge.

What I keep harping on is that you will bleed ions and their attendant energy out the cusps at any reasonable density.

Which density would be, what? The ions would take some of the electrons with them, and that should be visible.

Since we don't know whether the photo represents an operational shot or a diagnostic shot, we can't draw any conclusions concerning my analysis from the photo.

It's definitely a diagnostic shot, because it's described as a "test plasma". Since this is a garage scale operation, the difference may not be substantial.

[chrismb]

My goodness..... this exchange is such popycock.

I'll start another thread on this when I have time later, but this is just hunkumbunkum to eyeball that photo and tell anything at all.

the idea that this gas discharge glow is anything at all to do with showing where electrons are most dense is frustratingly misleading to anyone reading this and trying to get their head around it.

The 'luminescence' talked about for electrons ionising a background gas looks like this, and is charaterised by a spectrum running way up into many eV (i.e. into UV) whereas the fuzzy sub 1eV glow shown in the photo appears to be pure and outright recombination as entirely expected in a device you've just dumped 1000A and 10kV.

http://en.wikipedia.org/wiki/File:Cyclo ... r_view.jpg

[Art Carlson]

My goodness..... this exchange is such popycock.

Yep. At least as long as alexjrgreen refuses to calculate anything. I'm outta here.

[alexjrgreen]

At least as long as alexjrgreen refuses to calculate anything. I'm outta here.

Art, you're sitting on a grid computer. Of all the people here you're the most able to run the numbers.