Small update from Lawrenceville Plasma Physics

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

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Brian H
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Post by Brian H »

One of the Focusfusion.org bloggers with a bit of an inside track has now put the target for breakeven into 2011, though there's still a huge amount of "fuzz" around how fast things will progress once pB11 fusion is under way. I suppose 2010 is still possible.

Have you looked at the Intrade Focus Fusion page? The 'wager' is whether the Focus Fusion process will generate net power before midnight ET on 31 Dec 2014. I take that that that means usable power, not simply net thermal "scientific break-even".

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Brian H
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Post by Brian H »

New "Webinar" video. part 1 of 4:
http://www.youtube.com/watch?v=Kd-tWGWtYwU

Some technical info, mostly background in Part 1.

Edit: parts 2-4 are now up, with lotsa tech info and some Q&A.
Part 2: http://www.youtube.com/watch?v=-XK4cZMw ... re=related
3 & 4 linked on screen.
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Brian H
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Flickr slideshow

Post by Brian H »

There's a detailed construction and component assembly slideshow, with annotations, here: http://www.flickr.com/photos/focusfusio ... 8477/show/

Hold the mouse pointer on the info box to hold the image till you're ready for the next one. Click the "Show Info" button to toggle descriptions on and off.

About 140 pix. Lots of detail!
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chrismb
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Post by chrismb »

Thanks for pointing that one out, Brian. Nice to see a[t least one] project sharing all the interesting detail.

billh
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Post by billh »

Pretty cool. The slideshow was a bit like a history of civilization. You start in the early frames with a plumb bob and a T-square (known to the ancient Egyptians) and by the time you get to the end you have a fusion reactor!

happyjack27
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Post by happyjack27 »

Brian H wrote: Have you looked at the Intrade Focus Fusion page? The 'wager' is whether the Focus Fusion process will generate net power before midnight ET on 31 Dec 2014. I take that that that means usable power, not simply net thermal "scientific break-even".

The only activity to date is one bid to purchase at 22¢.
eeee... did i not know so much about "liquidity" and its affects, i'd take that bet.

kurt9
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Post by kurt9 »

More from Focus Fusion on Brian Wang's site (NextBigFuture):

http://nextbigfuture.com/2011/01/compac ... rates.html

The source information:

http://focusfusion.org/index.php/site/a ... _kev_ions/

chrismb
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Post by chrismb »

All strength to them.

But let's just check the reality; let's given them the benefit of the doubt and hit their upper ranges;

a) temp: In our best shot, on September 29, we calculate the average ion energy at between 160 and 220 keV

b) density: LPP physicists were able to calculate that the density of the plasma in the plasmoids is between 1 and 4X1020/cc

c) [from graph] tau: 300e-9s

Triple product reported; [22e4]x[4e26]x[3e-7] = 3e25 keVs/m^3

Lawson requirement for {>Q=1} >= 1e21 keVs/m^3

So the thing that worries me now is that with 4 orders of magnitude over the Lawson criterion, why is the thing still putting out only mJ outputs for kJ inputs? If that triple product were right, what's going wrong that it is still several oom below Q=1?


hmmmm.....

Skipjack
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Post by Skipjack »

Yeah just saw the news on NBF.
I am not quite sure what this really means since they have not reached break even yet.
Still, it is great to see that they are making progress and that they are getting results. I LOVE RESULTS!
Lets just hope they can get break even with PB11 and then I will open a bottle of champagne on them ;)

D Tibbets
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Post by D Tibbets »

chrismb, I need you to put your teaching cap on. To decipher your numbers I need to know how you determined them.
I can see how the energy output was determined from the neutron counts and formulas for D-D fusion. The input from current, though I don't know what the voltage was.
I've seen the triple product before and the Lawson criteria. Is this system an ignition machine? I thought not.
As far as the energy/ M^3 I could see this as a value for a given system, but without accounting for the input energy. And wouldn't the volume depend on density (or does this assume 1 atm? ....

Dan Tibbets
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Ivy Matt
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Post by Ivy Matt »

Skipjack wrote:I am not quite sure what this really means since they have not reached break even yet.
What this means is that there is no apparent barrier to producing pB11 fusion in the DPF. Whether it will produce useful amounts of energy is still up in the air.
D Tibbets wrote:The input from current, though I don't know what the voltage was.
There are a number of variables, and unfortunately they are not always reported on equally from update to update, so I've taken to keeping my own notes. LPP is aiming for a charging voltage of 45 kV, but last I heard they were using somewhere from 25 to 35 kV. As for the current, LPP is aiming for 2 MA per shot. Last I heard they had achieved 1.03 MA with a charging voltage of 30 kV and a fill pressure of 40 torr.
D Tibbets wrote:Is this system an ignition machine? I thought not.
Correct. A working DPF reactor would be pulsed.

Skipjack
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Post by Skipjack »

Thanks for the clarification Ivy Matt. That is what I thought.

KitemanSA
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Post by KitemanSA »

chrismb wrote: Triple product reported; [22e4]x[4e26]x[3e-7] = 3e25 keVs/m^3

Lawson requirement for {>Q=1} >= 1e21 keVs/m^3

So the thing that worries me now is that with 4 orders of magnitude over the Lawson criterion, why is the thing still putting out only mJ outputs for kJ inputs? If that triple product were right, what's going wrong that it is still several oom below Q=1?
That is the Lawson requirement for large, steady state, D-T plasmas. Were they running D-T. D-D, or p-¹¹B? Was it large? Was it steady state?

The Lawson criterion MAY apply, but the exact formulation may need to be adjusted and the VALUE will certainly be different for different fuels.

ladajo
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Post by ladajo »

As I understand;
D-D
Small
By definition, not steady state.

I do not think the criteria applies in this context. I would agree that it would need to be modified to fit the LPP model. I guess you could argue that the physics time scales involved are "steady state", but I would think that is obviated by the machine being a dynamic plasma event by design.

Ivy Matt
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Post by Ivy Matt »

On second thought, NIF is pulsed and aims to achieve ignition, so apparently I'm not clear on the concept of ignition. But, from what I understand, ignition is not a goal of LPP.

The current experiment, known as Focus Fusion-1, is not a steady-state device, nor would a working DPF fusion reactor be a steady-state device. By its nature it must be pulsed.

If by size we are referring to the volume of the vacuum chamber, it's small even compared to WB-6 and on, and it isn't intended to scale up like WB-D and DEMO, as it doesn't depend on external magnets for confinement. A working DPF fusion reactor, assuming it does work, would probably be the same size as the current experiment, plus whatever is needed for energy capture, cooling, and shielding. (Right now the shielding is the walls of the room that houses the FF-1 device.)

LPP is currently using only deuterium as the FF-1 fill gas. No tritium. Once they've found whatever they need to find with pure deuterium (I'm not quite clear what's left and rather impatient on this point. :lol:), they'll begin adding heavier gases, such as helium and nitrogen, to increase the atomic weight of the plasma without adding any unwanted nuclear reactions to the D-D fusion. This is to emulate plasma conditions under hydrogen and boron-11. Once they've tuned all the parameters to the right conditions, they'll move on to hydrogen and boron-11.

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