Well, Rick said we can kiss our behinds goodbye without the Wiffleball. That would seem to be definitive, unless I'm misunderstanding something.
He also said arcing is not a simple Paschen, but hasn't elaborated afaik.
STATEMENT OF OBJECTIVES from RFP
Thanks Dave!
Kiteman: The interacting factors of this simple machine are very complicated. It takes a very long time for it to all come together in a coherent whole.
May I suggest you re-read Valencia and supporting papers about 10 more times. Very Slowly. Then go back and read every bit of the discussions on NASA Spaceflight. Then all the technical discussions on this site. It is more material than can be covered in a few weeks. It is invaluable.
Tall Dave has been studying this for two years. He has discussed it extensively with Tom Ligon who ought to know. Tom does not spend much time here any more, but he did us the valuable service of leaving behind a trained cadre who are able to pick up beginners mistakes. It would be wise to defer to Dave if I'm too abrasive to deal with (it is not the first time I have had that complaint - however if you are going to deal with engineers it is a style that is rather common - some engineers think they are masters of the universe. A few of them actually are.).
Kiteman: The interacting factors of this simple machine are very complicated. It takes a very long time for it to all come together in a coherent whole.
May I suggest you re-read Valencia and supporting papers about 10 more times. Very Slowly. Then go back and read every bit of the discussions on NASA Spaceflight. Then all the technical discussions on this site. It is more material than can be covered in a few weeks. It is invaluable.
Tall Dave has been studying this for two years. He has discussed it extensively with Tom Ligon who ought to know. Tom does not spend much time here any more, but he did us the valuable service of leaving behind a trained cadre who are able to pick up beginners mistakes. It would be wise to defer to Dave if I'm too abrasive to deal with (it is not the first time I have had that complaint - however if you are going to deal with engineers it is a style that is rather common - some engineers think they are masters of the universe. A few of them actually are.).
Engineering is the art of making what you want from what you can get at a profit.
I don't think the direction of the opposite coil is important.
What is important is the alternating N-S-N-S at each vertex.
Gedanken experiment:
Build up the device 2 coils at a time.
Consider the first 2 coils on opposite sides of the sphere N-in & N-out both with their N poles Up.
They make a field at the center of the sphere yes.
Now add the adjacent pair of coils N-out & N-in ie. both with their N poles (almost) down.
They make a field at the center of the sphere that cancels that of the first coil pair except for a small lateral component.
Continue adding coil pairs around the device and if it is symmetrical all those lateral field components also cancel out.
This might be easier to see if you consider not just 6 coils but maybe 32 coils.
Where do the field lines go?
They go in through one coil and go out through the adjacent coils, not all the way across the machine. Line of least resistance.
Also a whiffle ball hole is a local phenomenon not much affected by the coils on the opposite side of the machine.
The concept of opposing coils was just a point of departure starting at the cusp machine. But the important thing about the cusp machine is that it demonstrates the stability of having the field line curvature convex toward the plasma at all points.
Do not hobble your thinking or options by keeping that history around treating it as gospel. It is a fossil of the evolution of the polywell concept.
What is important is the alternating N-S-N-S at each vertex.
Gedanken experiment:
Build up the device 2 coils at a time.
Consider the first 2 coils on opposite sides of the sphere N-in & N-out both with their N poles Up.
They make a field at the center of the sphere yes.
Now add the adjacent pair of coils N-out & N-in ie. both with their N poles (almost) down.
They make a field at the center of the sphere that cancels that of the first coil pair except for a small lateral component.
Continue adding coil pairs around the device and if it is symmetrical all those lateral field components also cancel out.
This might be easier to see if you consider not just 6 coils but maybe 32 coils.
Where do the field lines go?
They go in through one coil and go out through the adjacent coils, not all the way across the machine. Line of least resistance.
Also a whiffle ball hole is a local phenomenon not much affected by the coils on the opposite side of the machine.
The concept of opposing coils was just a point of departure starting at the cusp machine. But the important thing about the cusp machine is that it demonstrates the stability of having the field line curvature convex toward the plasma at all points.
Do not hobble your thinking or options by keeping that history around treating it as gospel. It is a fossil of the evolution of the polywell concept.
-Tom Boydston-
"If we knew what we were doing, it wouldn’t be called research, would it?" ~Albert Einstein
"If we knew what we were doing, it wouldn’t be called research, would it?" ~Albert Einstein
Tombo,
I think Having all N's facing the center is essential for oscillation.
Oscillation is better than recirculation (as popularly understood) because the supports become non-issues. (Well much less of an issue).
I wouldn't discount anything Dr. B did as "early days of the evolution". Dr. B was a very deep thinker. Very, very, deep.
I have studied his designs and I can tell you that from my examination none of the choices he made were of the "we will go with this for now" type. The designs are carefully integrated sets of ideas.
The 100 MW test machine was not just some number (100) pulled out of a hat. It represents the largest net power machine possible without exotic engineering. Dr. B was not only a great physicist (IMO) but he was one of the great engineers of our time.
I think Having all N's facing the center is essential for oscillation.
Oscillation is better than recirculation (as popularly understood) because the supports become non-issues. (Well much less of an issue).
I wouldn't discount anything Dr. B did as "early days of the evolution". Dr. B was a very deep thinker. Very, very, deep.
I have studied his designs and I can tell you that from my examination none of the choices he made were of the "we will go with this for now" type. The designs are carefully integrated sets of ideas.
The 100 MW test machine was not just some number (100) pulled out of a hat. It represents the largest net power machine possible without exotic engineering. Dr. B was not only a great physicist (IMO) but he was one of the great engineers of our time.
Engineering is the art of making what you want from what you can get at a profit.
Except that in WB6 for the 6 N pointing in (assuming that was the direction) the were 8 Ns pointing out. 6 physical (real) coils and 8 virtual ones.MSimon wrote: I think Having all N's facing the center is essential for oscillation.
He stated several times that WB6 was a rush job, put together to test one aspect. He also stated in his Valencia paper that he wanted true polyhedral coils, two models, WB7 and WB8.MSimon wrote: I have studied his designs and I can tell you that from my examination none of the choices he made were of the "we will go with this for now" type. The designs are carefully integrated sets of ideas.
You are mistaking a rush building job (as evidenced by using wire that had insulation inadequate for high temperatures) with rushed thought.KitemanSA wrote:Except that in WB6 for the 6 N pointing in (assuming that was the direction) the were 8 Ns pointing out. 6 physical (real) coils and 8 virtual ones.MSimon wrote: I think Having all N's facing the center is essential for oscillation.He stated several times that WB6 was a rush job, put together to test one aspect. He also stated in his Valencia paper that he wanted true polyhedral coils, two models, WB7 and WB8.MSimon wrote: I have studied his designs and I can tell you that from my examination none of the choices he made were of the "we will go with this for now" type. The designs are carefully integrated sets of ideas.
Engineering is the art of making what you want from what you can get at a profit.
Why?MSimon wrote:Tombo,
I think Having all N's facing the center is essential for oscillation.
What is the difference? (I think I know but I'm not sure.)MSimon wrote: Oscillation is better than recirculation (as popularly understood) because the supports become non-issues. (Well much less of an issue).
Why would it not support oscillation? The electrons are pulled into the device by the electric field. They would just orbit the field lines in the opposite handed direction.
Both effects must be going on simultaneously.
I try not to. But many of the rest of us mortals evolve our mental model.MSimon wrote: I wouldn't discount anything Dr. B did as "early days of the evolution". Dr. B was a very deep thinker. Very, very, deep.
Did he say explicitly anywhere that poles on the opposite sides must have their poles pointing the same way toward center.
The all N poles inward geometry simply falls out of the polyhedron chosen.
-Tom Boydston-
"If we knew what we were doing, it wouldn’t be called research, would it?" ~Albert Einstein
"If we knew what we were doing, it wouldn’t be called research, would it?" ~Albert Einstein
No, I am recongizing that certain choises are made by competent engineers that are good enough to get the current job done without being optimum. Round was good enough to get the job done (WB6) but as I read the Valencia paper he wanted two new machines of the same scale, one true cuboctohedron and one true icosododecahedron (square and pentagonal coils).MSimon wrote: You are mistaking a rush building job (as evidenced by using wire that had insulation inadequate for high temperatures) with rushed thought.
At least for the polyhedra of which I am aware, the two statements (opposites oppose and NSNS) are synonymous, though I don't know if the MUST be. But since all the ones we are talking of are, does it really matter?tombo wrote:I don't think the direction of the opposite coil is important.
What is important is the alternating N-S-N-S at each vertex.
He does say he wants "spaced angular corners" in the next machine. I note too that WB-7 has visibly wider spaces on the interconnects than WB-6 did.
In Valencia he states his proposed WB-7 and WB-8 will be "topologically similar to the original WB-2 and PZLx-1," which would seem to mean truncubes.
When I spoke to Bussard in May of 2007 on the radio interview, he said a dodec was the next logical step, and that higher-order polygons were probably not worth the diminshing returns -- but I think that was all in regards to a net-power attempt. At the time I remember reading only a truncube or dodec could work, but other sources such as the Polywell wiki now disagree, at least in theory.
In Valencia he states his proposed WB-7 and WB-8 will be "topologically similar to the original WB-2 and PZLx-1," which would seem to mean truncubes.
When I spoke to Bussard in May of 2007 on the radio interview, he said a dodec was the next logical step, and that higher-order polygons were probably not worth the diminshing returns -- but I think that was all in regards to a net-power attempt. At the time I remember reading only a truncube or dodec could work, but other sources such as the Polywell wiki now disagree, at least in theory.
Congradulations. You seem to be the first to get it and have a potentially significant issue.hanelyp wrote: Definitely replace the little nubs with something not passing through a cusp. Making the interconnects carry current like you propose would mess up the magnetic field around that corner. Picture a square with current being fed in through opposite corners, and out the other 2 corners. So instead of a short line funny cusp you get a cross shaped funny cusp, which I believe would be much leakier, and leave the inside corners of the square poorly shielded.
Do you have any contact with Indrek? I would like him (her?) to run my design thru his software to see if there are issues but (s)he wont respond.
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blaisepascal
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If you take a cubeoctahedron (which is the underlying geometry of the WB6/7 Polywells) and two-color the faces, you end up with eight faces of one color and six faces of the other color. Opposite faces of the cubeoctahedron will have the same color.KitemanSA wrote:At least for the polyhedra of which I am aware, the two statements (opposites oppose and NSNS) are synonymous, though I don't know if the MUST be. But since all the ones we are talking of are, does it really matter?tombo wrote:I don't think the direction of the opposite coil is important.
What is important is the alternating N-S-N-S at each vertex.
On the other hand, the octahedron alone has the important all-even-vertex property that allows the polywell to work. Two-coloring the octahedron yields 4 faces of one color, 4 faces of the other color, but opposite faces of the octahedron will have different colors.
If one were to build a polywell with underlying octahedral geometry, it would have 4 coils in a tetrahedral arrangement and real coils with N poles in would be facing virtual coils with S poles in.
Indrek is a he.KitemanSA wrote:Congradulations. You seem to be the first to get it and have a potentially significant issue.hanelyp wrote: Definitely replace the little nubs with something not passing through a cusp. Making the interconnects carry current like you propose would mess up the magnetic field around that corner. Picture a square with current being fed in through opposite corners, and out the other 2 corners. So instead of a short line funny cusp you get a cross shaped funny cusp, which I believe would be much leakier, and leave the inside corners of the square poorly shielded.
Do you have any contact with Indrek? I would like him (her?) to run my design thru his software to see if there are issues but (s)he wont respond.
He is on to other things.
Engineering is the art of making what you want from what you can get at a profit.
Good catch!! And I've been pushing an octohedron myself.blaisepascal wrote:On the other hand, the octahedron alone has the important all-even-vertex property that allows the polywell to work. Two-coloring the octahedron yields 4 faces of one color, 4 faces of the other color, but opposite faces of the octahedron will have different colors.
