emc2's website

Point out news stories, on the net or in mainstream media, related to polywell fusion.

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TallDave
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Postby TallDave » Thu Mar 18, 2010 2:38 pm

Tom Ligon wrote:My guess is that there are no nubs, but that they did what we've all thought of, supported the coils individually from the outside of the box.


It does look that way. Very interesting that they're doing this now. If they've eliminated the main source of electron losses then WB-8 results may be very, very exciting.
n*kBolt*Te = B**2/(2*mu0) and B^.25 loss scaling? Or not so much? Hopefully we'll know soon...

MSimon
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Postby MSimon » Thu Mar 18, 2010 2:50 pm

Betruger wrote:
MSimon wrote: Do you have a link?
This item:
http://www.hobbyspace.com/nucleus/index ... emid=19380


Thanks!
Engineering is the art of making what you want from what you can get at a profit.
http://protonboron.com/
THE OPEN POLYWELL FUSION CONSORTIUM

Betruger
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Postby Betruger » Thu Mar 18, 2010 3:02 pm

MSimon wrote:
Betruger wrote:
MSimon wrote: Do you have a link?
This item:
http://www.hobbyspace.com/nucleus/index ... emid=19380


Thanks!
It's the least I could do..
TallDave wrote:
Tom Ligon wrote:My guess is that there are no nubs, but that they did what we've all thought of, supported the coils individually from the outside of the box.


It does look that way. Very interesting that they're doing this now. If they've eliminated the main source of electron losses then WB-8 results may be very, very exciting.
So the support structures are omitted in the schematic?

Tom Ligon
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Postby Tom Ligon » Thu Mar 18, 2010 3:08 pm

Aside from eliminating nubs at the line cusp, individually supporting the coils simplifies interconnecting them and makes cooling one heck of a bunch simpler.

Even without cooling, it provides two lengths of heavy-gage copper conductor from each coil out to the world, so cooling between runs would be slightly quicker. But you could also make the coil from copper tubing, allowing you to try LN2 cooling to dramatically drop coil resistance, or even try high-temperature superconductor. Attemping any of these on a small-scale unit with the coils linked by nubs is a real construction challenge.

Finally, if you damage a coil, you can replace it easily, without tearing down the whole machine. This alone could save the program if time were tight.

Individually-supported coils costs more in chamber design and custom insulators, but makes so much sense I just hoped and prayed they had done it.

D Tibbets
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Postby D Tibbets » Thu Mar 18, 2010 3:43 pm

A few comments on prevous posts and some speculations:

From the EMC2 site pictures, I would guess the WB-D demensions as ~ 6 meters in diameter, assuming the man standing beside it is a little under 2 meters tall. IF the magrid size is ~ 1/2 the diameter of the chamber, this would be consistant with predictions for scaling (1.5 meter radius for breakeven). I speculate that the WB-D designation may suggest a new naming scheme. The D may refer to duterium fuel. Othe fuel combinations may use designations like -H for helium3, -B for boron 11, possibly even -T for a fallback deuterium- tritium reactor.

The coils will cool slowly in a vacuum by radiation alone. Compared to WB6, the magrid still has to be supported by outside posts. If each grid is supported by its own posts (like the drawing in the paper modeling the Polywell last fall) instead of one set of posts supporting the entire nub connected magrid, there may be even more area for conductive cooling. Also, the size/ surface area of the coils themselfs contribute Then there are conciderations about the number of windings per coil, wire gauge, thermal mass, post material/ thermal conductivity, etc. The posts in WB 6 were presumably ceramic, so any conductive cooling was probably mostly from the contained feedthrough wires. These could probably be larger and more numerous (a set for each coil) in WB8. So the cooldown time between shots could be similar to WB6 (or even shorter) despite the increased magnetic fields generated.
I had assumed that WB8 would be liquid nitrogen cooled because the targeted field strength (8X) was consistant with the electrical conductivity gain foe copper wire at that temperature. Certainly the brute force approach of more and/ or thicker windings with increased current in possibly larger coils could do this on it's own.

[EDIT]
As for test duration, I understand that in WB6 the magnetic field was first turned on , then the gas puffers and electron guns were fired. The magnetic current may have been run for over a second (I seem to recall several seconds being mentioned) for the pratical 1/4 millisecond tests.. If the subsequent setups had a tighter control on the timing of the various parameters, similar or perhaps longer tests might be doable, even with shorter magnet current times (with corresponding heating).

Dan Tibbets
To error is human... and I'm very human.

MSimon
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Postby MSimon » Thu Mar 18, 2010 4:11 pm

I like D for Demo.
Engineering is the art of making what you want from what you can get at a profit.
http://protonboron.com/
THE OPEN POLYWELL FUSION CONSORTIUM

Aero
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Postby Aero » Thu Mar 18, 2010 4:13 pm

Dan -
I copied the jpeg image into photoshop, sized it for convenience, cropped edge of the WB D box including the man and found the image to be 166 pixels high. I then cropped the man, head to heel, and found the image to be 49 pixels high. This gives the box as 3.387755102 times higher than the man is tall. For various man heights, I get the following:

Man Height WB D Height
inches meters meters
70 1.778003556 6.023440618
72 1.828803658 6.195538922
74 1.879603759 6.367637225
76 1.930403861 6.539735528
78 1.981203962 6.711833832
80 2.032004064 6.883932135

There might be a better way to estimate the box size.

Oh, does anyone have a comment about the internal structure illustrated in the WB D image?
Aero

Tom Ligon
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Postby Tom Ligon » Thu Mar 18, 2010 4:22 pm

You guys are sure trying to get a lot of decimals of precision out of a dream!

On the scale of WB-8, I count thirty bolt holes on the large flanges. According to the tech data at Insulator Seal, there are two flanges with 30 bolt holes. Their outside diameters are 13.25 and 14 inches, which pins down the size of the apparatus considerably. That would rough the magnet diameters at around half a meter, so maybe they were intended as 1/4 meter radius?

Simon, you beat me to it. D-for-Demo is probably the intent. If so, it also implies a higher degree of confidence than just another experiment in a sequence.

On the internal structure, possibly just to prevent bending of the large flat plates, but I'd like to think they represent a Venitian-blind collection scheme for alphas, a provision to test direct conversion.
Last edited by Tom Ligon on Thu Mar 18, 2010 4:33 pm, edited 1 time in total.

JohnSmith
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Postby JohnSmith » Thu Mar 18, 2010 4:31 pm

Hey Tom, don't say that. If I wake up now, I'm going to be really disappointed :(

This is awesome though, it's really promising that Dr. Nebel thinks it's possible. Maybe it's time to start tossing my Resume at them? :P

Tom Ligon
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Postby Tom Ligon » Thu Mar 18, 2010 4:36 pm

John,

Keep dreaming ... it is OK.

It's just that CherryPicker and maybe a few others here seem to be jumping the gun and assuming WB-D is funded already. I suspect the process requires that WB-8's work be completed, reviewed, and then run up the chain of command sufficiently high to uncork eight-figure funding.

What seems to be the case is it is on the drawing board, but unfunded, and they would love to have some contributions to get a head start on it. A nice design in-hand would improve the proposal, and reduce the amount of time scrounging for income before tackling the big project.

choff
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Postby choff » Thu Mar 18, 2010 4:52 pm

I just hope with all this buzz big oil doesn't start taking a negative interest, beware dinosaurs!
CHoff

MSimon
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Postby MSimon » Thu Mar 18, 2010 5:03 pm

choff wrote:I just hope with all this buzz big oil doesn't start taking a negative interest, beware dinosaurs!


You just sell it to them as a cheap heat source for enhanced recovery. Oil will not be going away soon. Immediately they have a greater concern from natural gas. What with new gas being discovered everywhere.
Engineering is the art of making what you want from what you can get at a profit.
http://protonboron.com/
THE OPEN POLYWELL FUSION CONSORTIUM

TallDave
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Postby TallDave » Thu Mar 18, 2010 5:28 pm


So the support structures are omitted in the schematic?


They seem to be implied based on the wiring.

Individually-supported coils costs more in chamber design and custom insulators, but makes so much sense I just hoped and prayed they had done it.


I figured it was too much to hope for, but it's nice to be surprised.
n*kBolt*Te = B**2/(2*mu0) and B^.25 loss scaling? Or not so much? Hopefully we'll know soon...

Aero
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Postby Aero » Thu Mar 18, 2010 6:33 pm

Tom Ligon wrote:John,

Keep dreaming ... it is OK.

It's just that CherryPicker and maybe a few others here seem to be jumping the gun and assuming WB-D is funded already. I suspect the process requires that WB-8's work be completed, reviewed, and then run up the chain of command sufficiently high to uncork eight-figure funding.

What seems to be the case is it is on the drawing board, but unfunded, and they would love to have some contributions to get a head start on it. A nice design in-hand would improve the proposal, and reduce the amount of time scrounging for income before tackling the big project.


Do you think that WB D, being a privately funded design, will evolve into something that falls under the Freedom of Information Act? Or will it forever stay beyond the visible horizon?
Aero

djolds1
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Postby djolds1 » Thu Mar 18, 2010 6:34 pm

MSimon wrote:I like D for Demo.
Or alternatively... DD, DT, or DHe3? Problems with getting Polywell to work with the pB11 fuel cycle?

Aero wrote:There might be a better way to estimate the box size.
Forget the man and use the pallet loader to estimate size.

Tom Ligon wrote:You guys are sure trying to get a lot of decimals of precision out of a dream!
Yeah yeah yeah, complaints complaints complaints... :twisted:
Vae Victis


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