Chapter 6

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

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MSimon
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Post by MSimon »

jcoady wrote:He mentions

"The chamber is ~2 meters wide and our
vacuum wavelength is 3.1915mm."

How big would the polywell device be inside the vacuum chamber.

The number we have been working with for coil dia is .3 m.
Engineering is the art of making what you want from what you can get at a profit.

Feebleminded
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Post by Feebleminded »

ladajo wrote:I love the Cap bank cage in the background of the pic on pages 65/66!
I noticed that too!

It seems like you'd need (as pictured) several of these at different angles to really understand the plasma distribution instead of just hoping the core size is ~20cm.

Image

jcoady
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Post by jcoady »

I redid the electric potential calculations using 3D poisson solver with a smaller polywell grid charged to 25 KV in a grounded cubed shaped vacuum chamber.

http://dl.dropbox.com/u/5095342/images/polywell14.jpg

Additional images of poisson solver mesh.

http://dl.dropbox.com/u/5095342/images/polywell13.jpg

http://dl.dropbox.com/u/5095342/images/polywell12.jpg

http://dl.dropbox.com/u/5095342/images/polywell11.jpg

DeltaV
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Post by DeltaV »

Hemispherical Luneberg lens. Cool.

Sweet job on the stainless welding, too.

DeltaV
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Post by DeltaV »

MSimon wrote:
jcoady wrote:He mentions

"The chamber is ~2 meters wide and our
vacuum wavelength is 3.1915mm."

How big would the polywell device be inside the vacuum chamber.

The number we have been working with for coil dia is .3 m.
If Fig. 5-7 is drawn to scale horizontally (it does say "Actual Measured Gaussian Beam") and the chamber is about 2 m wide, then the magrid coil spacing (between parallel planes containing the coil major diameters) is about 1/4 of that or ~0.5 m, which would fit with a 0.3 m coil diameter, considering the gaps.

[Edit] After playing around with those numbers in a drawing program, I now think the coils are closer to 0.4 m dia.

mvanwink5
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Post by mvanwink5 »

Was't there a previous estimate of 45 cm based on the EMC2 WB-8 named drawing and bolt count on the shown major flanges? I count 44 bolts though for the major flange shown in the picture on pages 65, 66. I looked for a matching standard vacuum flange to estimate dimensions, but flopped.
Best regards
Counting the days to commercial fusion. It is not that long now.

paperburn1
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Post by paperburn1 »

DeltaV wrote:
MSimon wrote:
jcoady wrote:He mentions

"The chamber is ~2 meters wide and our
vacuum wavelength is 3.1915mm."

How big would the polywell device be inside the vacuum chamber.

The number we have been working with for coil dia is .3 m.
If Fig. 5-7 is drawn to scale horizontally (it does say "Actual Measured Gaussian Beam") and the chamber is about 2 m wide, then the magrid coil spacing (between parallel planes containing the coil major diameters) is about 1/4 of that or ~0.5 m, which would fit with a 0.3 m coil diameter, considering the gaps.

[Edit] After playing around with those numbers in a drawing program, I now think the coils are closer to 0.4 m dia.
So basicly we are looking at 1/4 scale machine that has not been ramped up to anywhere near full potental (In many ways WB-8 is still operating well under capacity. The Marx Bank which charges the coils has been turned on, but only seven of the eventual 20 capacitors are connected. Even those seven capacitors have not yet been fully charged.) Be kind I am only good at math until they start putting letters in there. :)

mvanwink5
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Post by mvanwink5 »

So basicly we are looking at 1/4 scale machine that has not been ramped up to anywhere near full potental (In many ways WB-8 is still operating well under capacity. The Marx Bank which charges the coils has been turned on, but only seven of the eventual 20 capacitors are connected. Even those seven capacitors have not yet been fully charged.) Be kind I am only good at math until they start putting letters in there.
December 2011 paper..... status referred to is likely November 2011, which is ancient history.
Counting the days to commercial fusion. It is not that long now.

krenshala
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Post by krenshala »

mvanwink5 wrote:
So basicly we are looking at 1/4 scale machine that has not been ramped up to anywhere near full potental (In many ways WB-8 is still operating well under capacity. The Marx Bank which charges the coils has been turned on, but only seven of the eventual 20 capacitors are connected. Even those seven capacitors have not yet been fully charged.) Be kind I am only good at math until they start putting letters in there.
December 2011 paper..... status referred to is likely November 2011, which is ancient history.
But it does give us something to base our "I think they are here on the progress chart" speculation on. ;)

MSimon
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Post by MSimon »

Now, where does one store the borax aboard ship?
How many years worth of fuel do you want to carry with you?
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 »

jcoady wrote:"The coils will eventually be charged up to 25kV."

I implemented a Poisson Solver in MATLAB for a charged magnetic grid inside the vacuum chamber.
Nice.

Have you considered implementing a 1/8 sector rather than a 1/2? Might allow a small bit of extra resolution.

But nice none-the-less.

jcoady
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Post by jcoady »

KitemanSA wrote:
jcoady wrote:"The coils will eventually be charged up to 25kV."

I implemented a Poisson Solver in MATLAB for a charged magnetic grid inside the vacuum chamber.
Nice.

Have you considered implementing a 1/8 sector rather than a 1/2? Might allow a small bit of extra resolution.

But nice none-the-less.

I actually implemented poisson solver for the whole device, and in order to visualize what the results were inside I split the mesh down the middle and plotted the result using MATLAB. I haven't tried just solving for a 1/8 sector yet. For the 3D tetrahedral mesh resolution I have an adaptive mesh that has a finer resolution around the magnetic grid and lower resolution as you move away from it.

MATLAB has a whole bunch of 3D visualization tools so there are many ways to look at the results. For instance you can slice up your 3D mesh to visualize along different planes like this.

http://www.mathworks.com/help/techdoc/ref/slice.html

Other visualization mechanisms like 3D plots, isosurfaces, contours are also available in MATLAB.

http://www.mathworks.com/help/techdoc/v ... liccy.html

paperburn1
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Post by paperburn1 »

MSimon wrote:
Now, where does one store the borax aboard ship?
How many years worth of fuel do you want to carry with you?
Everybody knows you carry the borax in the laundry..... (drum roll cymbal crash)

Tom Ligon
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Post by Tom Ligon »

Rolls of boron wire. Each atom makes 6 electrons move at something like 1.3 million volts. Work the energy per ton out from there, but it is a bunch.

TallDave
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Post by TallDave »

Very, very interesting. Thanks for sharing.

The electron gun is being repaired

Heh.

The density has a rapid increase which slows for most of the shot before rapidly decaying at the end. This particular shot used all 6 coils but no electron gun. The coils will eventually be charged up to 25kV. For this shot the coils were not charged. Assuming that the plasma is approximately 20cm in diameter, the peak density is around 4.2e12 cm^-3

Hmmmm...
n*kBolt*Te = B**2/(2*mu0) and B^.25 loss scaling? Or not so much? Hopefully we'll know soon...

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