STATEMENT OF OBJECTIVES from RFP

Discuss how polywell fusion works; share theoretical questions and answers.

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MSimon
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Post by MSimon »

The nubs are only a problem where they are. Most folks argee they need to be moved.
I want them moved to the far side of the moon. I'll settle for 3 blocks away from the vacuum chamber.

No unshielded metal. None. Zero. Nada. Zilch.

But I will compromise: unshielded metal can comprise 1E-8 of the intercepted area at the coil radius. (R0 being the center of the coil configuration). That should give you about 12 pieces of tinfoil.

Dr. B. says the nubs are bad. The latest Navy contract says the nubs are bad. So let us figure out how to do it without nubs.

It is some times very dangerous being too smart by half.

KISS -

The design presented is brilliant for a liquid cooled fusor grid. Brilliant. Absolutely brilliant. A tour de force. We are not building a fusor.
Engineering is the art of making what you want from what you can get at a profit.

MSimon
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Post by MSimon »

Electron losses must be kept below 1E-5. That includes upscattering and losses to unshielded metal.
Engineering is the art of making what you want from what you can get at a profit.

KitemanSA
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Post by KitemanSA »

MSimon wrote:
The nubs are only a problem where they are. Most folks argee they need to be moved.
I want them moved to the far side of the moon. I'll settle for 3 blocks away from the vacuum chamber.
No unshielded metal. None. Zero. Nada. Zilch.
Yet you seem to want to insert a forest of connections between the round coils (which DrB didn't want) and the shell. Whereas my proposal has, to quote ... oh, YOU, "No unshielded metal. None. Zero. Nada. Zilch." That is what I think DrB wanted.
MSimon wrote:Dr. B. says the nubs are bad. The latest Navy contract says the nubs are bad. So let us figure out how to do it without nubs.
It is some times very dangerous being too smart by half.
KISS -
The nubs are bad when they are in the middle of the funny cusp. The funny cusp is a stretch (long with round coils, hypothetically much shorter with "square" plan form coils) that is unshielded space and thus the nubs can only deflect electrons as a function of the paultry current they carry thru themselves. Placed away from the point of the funny cusp, the cross-connects are shielded by the wiffleball magnet field. Thus, "no unshielded metal. None. Zero. Nada. Zilch." You can have cross connects (nubs) just not THERE.
What is more, the design I am proposing has NO nubs, as you seem to be defining them, and no more support - I/O headers than the WB-6. The cross connects in my proposal are shielded by the same magnitudes of current as the main arcs of the magnets. Nothing unshielded, NZNZ.
MSimon wrote:The design presented is brilliant for a liquid cooled fusor grid. Brilliant. Absolutely brilliant. A tour de force. We are not building a fusor.
The design I am trying to present with Tombo's fabulous graphical help, should have a field that is as strong as, and be more spherical than, the large scale WB-6 you all seem to be pushing. DrB DIDN'T want the WB-6 configuration of magnet. I think he was on to something. Why don't you?

Billy Catringer
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Post by Billy Catringer »

KitemanSA wrote:Yet you seem to want to insert a forest of connections between the round coils (which DrB didn't want) and the shell. Whereas my proposal has, to quote ... oh, YOU, "No unshielded metal. None. Zero. Nada. Zilch." That is what I think DrB wanted.

Just two supports per magnet, provided the shell of the vessel is not too far away.
KitemanSA wrote:The design I am trying to present with Tombo's fabulous graphical help, should have a field that is as strong as, and be more spherical than, the large scale WB-6 you all seem to be pushing. DrB DIDN'T want the WB-6 configuration of magnet. I think he was on to something. Why don't you?

I do not doubt that Doctor Bussard was on to something. That is not the issue. Constructability is the issue. We need something that works right now, not something that we will only be able to build twenty or thirty years from now at best. You and Doc Bussarrd wanted the baseball stitch. Okay, I want it too. Guess what? We can't build any time soon and I for one am not willing to wait if the simpler design will do the job.

KitemanSA
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Post by KitemanSA »

Billy Catringer wrote:
KitemanSA wrote:Yet you seem to want to insert a forest of connections between the round coils (which DrB didn't want) and the shell. Whereas my proposal has, to quote ... oh, YOU, "No unshielded metal. None. Zero. Nada. Zilch." That is what I think DrB wanted.
ust two supports per magnet, provided the shell of the vessel is not too far away.
Then your magnet structure will have hellacious bending loads. Big, thick structure... yuck.
Billy Catringer wrote:
KitemanSA wrote:The design I am trying to present with Tombo's fabulous graphical help, should have a field that is as strong as, and be more spherical than, the large scale WB-6 you all seem to be pushing. DrB DIDN'T want the WB-6 configuration of magnet. I think he was on to something. Why don't you?

I do not doubt that Doctor Bussard was on to something. That is not the issue. Constructability is the issue. We need something that works right now, not something that we will only be able to build twenty or thirty years from now at best. You and Doc Bussarrd wanted the baseball stitch. Okay, I want it too. Guess what? We can't build any time soon and I for one am not willing to wait if the simpler design will do the job.
Where on Earth are you getting that ridiculous "20 or 30 years from now"? Please don't condemn something you appear not to understand. I am building a model of the cryo-copper unit now. I hope to have it done in a few weeks. The construction mechanics will be quite simple for cryo-copper. The tooling for the SC will be more complicated, but still quite straight forward, as long as the unit is BIG enough. There are certain minimum bend radii to take into account with SCs.

KitemanSA
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Post by KitemanSA »

Skipjack wrote:The very first (working) nuclear reactor ever built was not fit to be put into a submarine either...
I would say: build something that works (no matter what) first, then think about making it fit into a sub or whatever.
Too true.
And remember, the Navy has many more surface ships than submarines, and most of them are wanting power levels in the 100MW range for all their whizz-band Buck-Rogers weaponry. Make a functioning power source 10m in diameter and they can EASILY fit most surface ships around it!

MSimon
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Post by MSimon »

The current set up has four stalks.

And yet the focus is on nubs.

My take: stalks are not a problem because electrons don't circulate. They oscillate.

All you need to do (there may be some other things like a high resistance conductive coating on the stalks to make the gradient on the stalks match the field gradient) is keep the stalks in the grid shadow.

And the current stalk set up (if it conforms to the WB-6 pattern) is not even fully in the shadow.
Engineering is the art of making what you want from what you can get at a profit.

KitemanSA
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Post by KitemanSA »

MSimon wrote:The current set up has four stalks.
Yup, so would my proposal, but they would be in tension (don't NEED to be, I just prefer it).
MSimon wrote:And yet the focus is on nubs.
Yup, those little thingees RIGHT IN THE MIDDLE of the funny cusps. No protection at all! Make them a pair, one either side of the funny cusp, and make the cusp short like it seems DrB was trying to do with his rounded corner "square" plan-form coils, and TA-DA, nothing in the funny cusp either. Besides, I would make them carry currents of the same magnitude as the main magnet arcs, so they would be magnetically protected.
MSimon wrote:My take: stalks are not a problem because electrons don't circulate. They oscillate.
To a point, I agree, but I still want them minimized, all else being equal.
MSimon wrote:All you need to do (there may be some other things like a high resistance conductive coating on the stalks to make the gradient on the stalks match the field gradient) is keep the stalks in the grid shadow.
And the current stalk set up (if it conforms to the WB-6 pattern) is not even fully in the shadow.
That is what I originally proposed for the nubs, back them off and coat them, but someone poo-pooed that idea.

hanelyp
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Post by hanelyp »

KitemanSA wrote: Yup, those little thingees RIGHT IN THE MIDDLE of the funny cusps. No protection at all! Make them a pair, one either side of the funny cusp, and make the cusp short like it seems DrB was trying to do with his rounded corner "square" plan-form coils, and TA-DA, nothing in the funny cusp either. Besides, I would make them carry currents of the same magnitude as the main magnet arcs, so they would be magnetically protected.
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.

MSimon
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Post by MSimon »

Dudes,
Definitely replace the little nubs with something not passing through a cusp.
The cusps are all the open spaces between the coils. Stalks do not pass through the cusps.

NO GD UNSHIELDED METAL

GD? It is a technical term. Ask a sailor.

Still unanswered questions:

1. Torque on the "V'
2. Delta P on the LN2 circuit
3. Total heat load on the LN2 circuit

BTW my estimate is that torque on the "V" is your worst problem.
Engineering is the art of making what you want from what you can get at a profit.

Billy Catringer
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Post by Billy Catringer »

MSimon wrote:The current set up has four stalks.

And yet the focus is on nubs.

My take: stalks are not a problem because electrons don't circulate. They oscillate.

All you need to do (there may be some other things like a high resistance conductive coating on the stalks to make the gradient on the stalks match the field gradient) is keep the stalks in the grid shadow.

And the current stalk set up (if it conforms to the WB-6 pattern) is not even fully in the shadow.

Round vessel walls, shadows fan out in a conical patter. If keeping them in the shadows works for the physics, it works real well for the structure. It would let us get away with using four supports per magnet and that is an enormous help.

MSimon
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Post by MSimon »

BTW there will be no nubs in WB-100. Because they will melt.

Might as well get rid of them now.
Engineering is the art of making what you want from what you can get at a profit.

Billy Catringer
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Post by Billy Catringer »

MSimon wrote:BTW there will be no nubs in WB-100. Because they will melt.

Might as well get rid of them now.

I decided that a long time ago. They were an obvious problem for more than one reason.

KitemanSA
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Post by KitemanSA »

MSimon wrote:Dudes,
Definitely replace the little nubs with something not passing through a cusp.
The cusps are all the open spaces between the coils.
Nope, the cusps are the center points of the "In" coils and real or virtual "Out" coils. The spaces between the coils are the funny cusps, and are only long (quasi-linear) with round plan form coils. They should become more point-like with a "square" plan form coils set, and VERY point-like with the "real/real" coil set-up like the modified MPG lay-up proposed.
MSimon wrote:Stalks do not pass through the cusps.
Neither do my cross braceing coils.
MSimon wrote: NO GD UNSHIELDED METAL
GD? It is a technical term. Ask a sailor..
That's right, no MF unshieled metal.
MF? Its a technical term. Ask a street hood.
MSimon wrote:Still unanswered questions:
1. Torque on the "V'
It appears we are not talking the same language. What "V" exists to receive the torque? I can see the torque GALORE on the point supported round plan-form coils from a WB-6 knock-off, but I see none in my idea. Just "Xs".
MSimon wrote:2. Delta P on the LN2 circuit
3. Total heat load on the LN2 circuit.
So you say, and if so, the MPG varient proposed can still be wound as individual coils. More plumbing, etc, but still the better performance.
MSimon wrote:BTW my estimate is that torque on the "V" is your worst problem.
??? No "Vs", no problem, no?

MSimon
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Post by MSimon »

Nope, the cusps are the center points of the "In" coils and real or virtual "Out" coils.
I take it you are unfamiliar with line cusps. Art Carlson seems to think they are a fact of life. Perhaps you need to have a go with him and explain why line cusps are a figment of his imagination. I'm sure he will be most grateful for the education.
Engineering is the art of making what you want from what you can get at a profit.

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