We Will Know In Two Years

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

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MSimon
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Postby MSimon » Mon May 25, 2009 2:27 am

Also note: the SC leaks have a LOT in common with a Polywell - SC magnets in a vacuum chamber with lots of particles wizzing by. The only thing missing is a grid voltage.

Once science becomes overtly politicized reason and rationality are left behind. As Dr. B used to say: it is not really criminal. It is human nature.
Engineering is the art of making what you want from what you can get at a profit.

chrismb
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Postby chrismb » Mon May 25, 2009 7:54 am

MSimon wrote:I still like what Nick Krall (a fan of Bussard's work and considered one of the top plasma experts in the world) had to say on the subject:

"We spent $15 billion dollars studying tokamaks and what we learned about them is that they are no darn good."

Let's just make sure we get the perspective right here.

If I was an alien visiting from a planetary system far away (and believe me, it feels that way very often!) and I was the 'nuclear fusion capability inspector' I would simply want to know if humans could;

'Stage 4'; generate continuous, on-demand over-net energy from a fusion process. That would be my principle investigation. A sub-set of that would be;

'Stage 3'; generate continuous, on-demand over-net-enery neutron emissions from a fusion process. That would be my secondary investigation, because the production of neutrons is far and away the easiest nuclear reaction to get going and neutrons are a good energy vector to get energy out of a reaction volume. (Deuterium is universally widespread, but a more advanced civilisation would be able to burn something else and move up to stage 4.)

'Stage 2'; generate continuous, on-demand, controlled neutron emissions from a fusion process.

'Stage 1'; generate on-demand neutron emissions from a fusion process.

'Stage 0'; experiments preluding nuclear fusion

...and then I introduce myself as a galactic fusion inspector to the world' leaders and scientists and say 'take me to see your most advanced fusion reactor'. What would you go take me to see?

Large Helical Device - stage 0
WX-7 - stage 0
H- bomb - stage 1
JET - stage 1
Polywell - 'nuanced' stage 1
Farnsworth fusor - stage 2.

So what's going on here - we're a 'stage 2 fusion technology planet' *because of* a simple two-electrode device built in the 1950's and is currently being built by amateurs!

Now consider ITER - it's trying to jump straight to stage 3, while polywell is trying to jump to stage 4! It just seems to me to be, well..er.. not sure of a good word other than 'immature'. These experiments just need to knuckle down and focus on getting out a continuous stream of neutrons because at the moment, as the Galactic inspector asks 'got any stage 4..got any stage 3...' he'll [it'll!?? whatever passes for gender on his home planet] get to 'got any stage 2' and mankind will duly present him with a Farnsworth fusor, at which point he ticks the box 'stage 2' and moves on to the next planet for inspection. ITER, Polywell - didn't get a look-in on the galactic register! Stage 1 technologies with unrealistic, or at least excessive, expectations.

Art Carlson
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Postby Art Carlson » Mon May 25, 2009 8:50 am

That's a funny set of criteria your inspector has. If a planet has an economical laser fusion power plant, or an economical tokamak power plant with a 24 hour pulse length and a duty factor of 0.95, they would be classed as Stage 1 because the power plant does not operate steady state. If a planet has a 100 kV accelerator smashing deuterons into deuterated parafin, they would be classed as Stage 2, even though the technology is a dead end that will never produce net power.

chrismb
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Postby chrismb » Mon May 25, 2009 9:09 am

Art Carlson wrote:That's a funny set of criteria your inspector has. If a planet has an economical laser fusion power plant, or an economical tokamak power plant with a 24 hour pulse length and a duty factor of 0.95, they would be classed as Stage 1 because the power plant does not operate steady state. If a planet has a 100 kV accelerator smashing deuterons into deuterated parafin, they would be classed as Stage 2, even though the technology is a dead end that will never produce net power.
I would add it as a 1* category - the recovery of net-power from discontinuous fusion. (Otherwise we already have viable fusion power - we just have to keep setting off H-bombs!) Doing a series of pulses doesn't demonstrate an understand of any technology to *control* fusion.

A continuous 100kV beam into deuterium is, indeed, continuous fusion and is exactly what a fusor does!

The point of the categories is that you start off with 'stage 4', which you don't seem to have an argument about, then all I've done is peel back the layers of that onion to reveal the objectives that the experiments should be aiming for, en route.

[Maybe I missed a point; are you saying that there is something *evidentially* non-viable about beam-target systems? What is the basis for that rationale? Or maybe it's what thermal plasma fusion scientists like to tell themselves. A beam into a block of paraffin is a dead end in as much as in that case there are too many lossy electrons that soak up the beam's energy, but that's just *that* particular experiment, just like JET is a dead-end if you were to be focussing on the immediate viability of a particular experiment.]

tombo
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Postby tombo » Mon May 25, 2009 10:34 am

MSimon wrote:And I forgot to mention that alphas leaving through a cusp greatly simplifies direct conversion.


Do we have an estimate yet of the thermal flux at the magrid with that consideration (the bulk of the alphas going through the holes) in mind?
If it came through I missed it.
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bcglorf
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Finally something I can answer

Postby bcglorf » Mon May 25, 2009 1:58 pm

Chrismb:But I have presented an argument. What argument successfully argues for mealy-mindedness and whimpish half-measures?

Working at a mostly government funded university has prepared me for this question. The answer is bureaucracy.

When funding is coming in from a variety of governments all forming their own committees to decide what to fund and for how much, the funding that gets provided and why is NOT gonna make any sense, to anybody. Not even the individuals on the committees. The reason ITER's funding doesn't make collective sense is because the real minds behind everything ultimately just want as much money as they can get to do the research and rational arguments don't survive committees so the instead any and every argument and reason to fund the project is put forward in the hopes that more will stick.

TallDave
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Postby TallDave » Mon May 25, 2009 3:44 pm

Art Carlson wrote:
TallDave wrote:I had understood p-B11 temps to be challenging for tokamaks, but I'm not clear on why exactly. Possibly it was just the cyclotron radiation issue, or maybe just high temps in general relative to their difficulty in IEC.

I've heard it said before (also by Bussard?) that tokamaks have trouble reaching high temperature, but I've never heard it from the tokamak community. The optimum temperature for a pressure-limited, homogeneous D-T plasma is 15 keV, and the optimum maximum temperature for a D-T tokamak with a realistic temperature profile is around 30 keV, so nobody was much interested in higher temperatures. There is a well-known and well-understood beta limit in tokamaks, and a well-known but not so well understood density limit, so there is in a sense a lower limit on temperature, but in practice no upper limit except, under some conditions, available heating power.


Well, OK, but weren't tokamaks adopted as the leading magnetic confinement scheme because everyone was so excited by the Russians' initial 1000eV performance? Farnsworth was already operating at 10x those temperatures well before that iirc (with much worse losses of course). Maybe it would be fair to say temperature is not a problem anymore thanks to lots of expensive engineering?

Art Carlson wrote:
TallDave wrote:As I understand and recollect it, the thermal tail problem is the side reactions you get because the distribution is Maxwellian, which make the process somewhat less aneutronic. Someone did a post on this a while back, pointing out the conventional calculations for aneutronic fusion assumed such a distribution.

OK, if that's what you mean. The thermal tail puts a limit of how clean p-B11 can be (very clean vs. super clean), but not on the feasibility of net power.


Yeah, just a limit on the aneutronicity. That has some commercial implications, of course.

PolyGirl
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WB8 Considerations

Postby PolyGirl » Tue May 26, 2009 1:13 am

Just a few things to consider.

Dr Bussard during his Google Talk starting around 0:12:40 and finishing 0:13:00 states “One of my friends Nicolas Krall a consultant to us, probably one of the top 3 theorists in the world said some years ago we spent 15 Billion dollars studying the Tokamaks and what we know about them is that they are no darn good.” A very memorable moment indeed, because the audience laughs at the end of the statement.

In regards to some insight as to what WB8 will be, one can consider the article Alan Boyle did on the update of the polwell.

The team has turned in its final report, and it's been double-checked by a peer-review panel, Nebel told me today. Although he couldn't go into the details, he said the verdict was positive.

"There's nothing in there that suggests this will not work," Nebel said. "That's a very different statement from saying that it will work."

By and large, the EMC2 results fit Bussard's theoretical predictions, Nebel said.

and in response to Mr Bowery in the comment section, Dr Nebel said

Yes, there are neutrons and the numbers are consistent with the plasmas we are measuring. However, neutrons can be deceptive. A lot of fusion researchers have gotten in trouble in the past by relying on these types of measurements. You need to know where they come from and that's difficult to measure.

and again in the comment section Dr Nebel responds directly to Dr Miller with

First of all, our work has been peer reviewed. An independent panel of experts has looked at these results. I don’t believe that there was anyone on the panel who has less than 40 years experience working with magnetic confinement. It included senior professors and people who have managed the fusion program. We asked them for their honest opinions and that’s exactly what we got. We are proceeding with our program in line with their recommendations.

and

Despite the skepticism, Nebel and his colleagues have already drawn up a plan for the next step: an 18-month program to build and test a larger fusor prototype. "We're shopping that around inside the DOD [Department of Defense], and we'll see what happens," he said.


So, summing up neutrons were detected in WB7, thus confirming the WB6 results, which confirmed Dr Busards theoretical result. This enabled further research to be done as a result of the further funding being provided. This enables the EMC2 team to proceed with their program to “build and test a larger fusor prototype. The only question is, whether this larger size Polywell is going to be continuous or pulsed?

Regards
Polygirl
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TallDave
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Postby TallDave » Tue May 26, 2009 1:37 am

Thanks for reminding me of that last quote, PolyGirl, I had forgotten that. At the time I assumed he meant he was shopping WB-100, but given the RFP now I wonder (EDIT: Or did I? Based on link below, looks like I was thinking water-cooled, which also now seems wrong; the challenge of holding the field at beta=1 is probably minor relative to the question of loss scaling.)

OTOH, can anyone actually tell how large/powerful WB-8 could be? I don't see any numbers on the RFP itself...

https://www.fbo.gov/index?s=opportunity ... =1&au=&ck=

I'm assuming this can't be WB-100 because it doesn't say anything like "test reactor" and $20-40M per year would have gotten more attention. Anyone have an idea what the upper dollar limit on a solicitation like this would be?

I would love to see some 1T test results at any size they can cram it into. That would really be exciting.
Last edited by TallDave on Tue May 26, 2009 1:49 am, edited 3 times in total.

PolyGirl
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WB8 Considerations

Postby PolyGirl » Tue May 26, 2009 1:45 am

Looking further and reflecting (I should have done more searching).

The second consideration should have been in WB-8 Coming and it was discussed a lot further in Design of next device WB-8

Hopefully the links will help others.

Regards
Polygirl
The more I know, the less I know.

Aero
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Postby Aero » Tue May 26, 2009 2:06 am

Earlier someone asked the question along the lines of, "What happens to WB-7.1?" Meaning, is WB-7.1 going to be cannibalized for parts to build WB-8. I think this quote from the solicitation addresses that in an obscure way.
as well as requirements to provide the Navy with data for potential applications of polywell fusion with a delivered item, wiffleball 8 (WB8) and options for a modified wiffleball 8 (WB8.1) and modified ion gun

I read this to say that the navy intends to take possession of WB-8. I seriously doubt that the navy wants "used" parts and I believe that the vacuum chamber is EMC2's property which I doubt they will willingly part with.
In other words, it is my guess that WB-7.1 will remain operational in Santa Fe until nothing more can be learned from it.
To someone who can read navy contracteeze, am I right? And if so, what sort of machine would be useful to the navy in these circumstances? I recognize that the navy has top notch science and tech people at China Lake, so they will have the needed skills, whatever skills they may need.
Aero

gblaze42
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Postby gblaze42 » Tue May 26, 2009 4:29 am

Art Carlson wrote:
gblaze42 wrote:Now I do not know who you are, but from where I stand Dr. Nebel is the only one working on a real Polywell fusion device, that makes him the expert, he has the data and that trumps theory. I hope you don't mind if I take his word over yours.

Feel free. But if you are a scientist, you know that lots of things can go wrong with experiments, from faulty instruments to faulty interpretation, so it's not a good idea believe experimental data blindly. Unfortunately, that is what we have to do with Dr. Nebel's data. None of us has ever seen it. We don't even know what instruments he was using. At least I have laid my theory on the table for your inspection.

Well I wasn't able to complete my doctorate as the funding dried up for my position, but yes I do know just how many things can go wrong, I can tell you how many man hours I actually had to redo testing for neutron activation for a certain detector we were working on. But I digress, from what Dr. Nebel stated, he has gone through a review process that would most likely include scientists in the employ of the Navy. I can't imagine he would let the information he collected into the public domain or discuss the experiment due to an obvious NDA.
The problem really is if we knew all there is about fusion we would have a working q=1 reactor by now, obviously there's a lot more to learn and discover before we get there. Nebel's got my attention, I seriously didn't have to much hope for Polywell, but then I think every stone we turn over will eventually lead us to the one that will work, if only by defining the problem by what didn't work.

KitemanSA
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Postby KitemanSA » Wed Jun 17, 2009 5:33 am

rnebel wrote:The major focus for the next generation Polywell is transport. We will be trying to take the machine from "OK" confinement to "good" confinement. Historically, this is a step that has been difficult for fusion machines. The next couple of years are going to be interesting.
Dr. Nebel,

What can you tell us about WB7.1?

rnebel
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Postby rnebel » Wed Jun 17, 2009 11:25 pm

Not a whole lot. The WB7.1 is being used to address some issues we uncovered with the WB-7. It doesn't have a lot more capability than the WB-7, but we will use what we learn from it to better design the WB-8. We will also be testing and validating some diagnostics.

KitemanSA
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Postby KitemanSA » Sat Jun 20, 2009 12:45 am

Dr. Nebel,

Any pictures available? I'd like one for the wiki.


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