Why Not Just Build The Darn Thing

Discuss the technical details of an "open source" community-driven design of a polywell reactor.

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MSimon
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Post by MSimon »

vankirkc wrote:
TallDave wrote:
MSimon wrote:You would be surprised at what kind of loose change is out there for blue sky work.
No kidding. Every year some yahoo claims to have an data compression algorithm that violates the mathematical limit, and there always seems to be someone willing to fund them. They usually disappear around prototype testing time.

And that crazy hydrino theory keeps getting money somehow.

An X Prize would help a lot, though.
So you're saying that every year someone dumps $40 million into one of these projects? Hell, I should change my line of work!

My guess is that they aren't. Rather, they might be funding a few 10s or 100s of thousands at most. This goes to my scale suggestion. Starting smaller will open the door to more funding prospects.

As for the hedge fund, I would imagine that the way that works is you get the $5m, and if you are able to produce results then they can ramp you up to $35m. The operative word here is producing results, which you aren't going to be able to do if you shoot for the WB-100 moon to start with.

Anyway, just a suggestion.
I am not at liberty to say what goes on under the radar. But let me put it this way: you are wrong.
Engineering is the art of making what you want from what you can get at a profit.

Roger
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Post by Roger »

My guess is that they aren't. Rather, they might be funding a few 10s or 100s of thousands at most.
Not been following things too close, eh?

I almost had 3 mill for Polywell from Earth Trust about 2 yrs ago. You might be surprised how easy it is to bump into real hard cold cash. And Lerner has done much better than that, 7 mill to start and more later, 10's of millions IIRC.
I like the p-B11 resonance peak at 50 KV acceleration. In2 years we'll know.

Jboily
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Post by Jboily »

MSimon wrote:
KitemanSA wrote:
MSimon wrote:So my thinking is to ask for $40 million.
So how much can we get the various suppliers to "invest" in order to obtain the ARPA-E funding? Given the state of the economy, will they kick in 30% to 50% of the price of their equipment? The max amount of ARPA-E funding was smaller than the $40M shown.

Otherwise, who gets "asked" for the money?
Yeah. That is one way to go. I like being able to offer top dollar for superior service - i.e. I want to be able to jump to the head of the line. I want the deal to be profitable. A happy supplier is easier to deal with. We shouldn't make them too happy though.

Who gets asked? Who ever. Since it is a Navy Project how about more Navy funds?
I may be a bit late to jump in this discussion at this time, but I have an idea.

I can come up with about 40% of the R&D funds required in Gov. help. Assuming the $40M can be divided as $5 administration and local, $5M R&D salaries, and $30M hardware; I could get $2 in cash to cover part of the salary and about $10-15M for the hardware. Some loan facilities could also be arranged I the order of $10M, maybe more, as long as more then 25% of the project comes from investors.

There are a few strings attached. Only the R&D work performed in Canada counts, is one of them. But I think this should not be a problem for some of you. Some work could be done outside Canada, but this work would not generate extra cash. I think USA gov. funds (TBD) may affect these numbers.

I have a good idea of a perfect location for a full power test facility, where shielding would not be a problem.

Is this could be of help?

MSimon
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Post by MSimon »

You should share your proposal with EMC2. If they buy in I have a management team ready to go.

BTW I believe a 1 m dia (coils) 3T continuous operation machine could be built for around $10 - $15 million.

Canada is not a problem. There are some IEC folks up there that I would love to drag in. Contact me by e-mail for details. (see the sidebar at IEC Fusion Tech)
Engineering is the art of making what you want from what you can get at a profit.

D Tibbets
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Post by D Tibbets »

93143 wrote:
Roger wrote:
93143 wrote: I'd expect much more comprehensive test results...
Publishing ban.

Duh.
Careful. I thought it was fairly clear that I meant more comprehensive results than WB-6, not more comprehensive results than they've showed us so far. I know all about the publishing ban and I don't expect them to show us the data for a while.
chrismb wrote:Is there any indication over what drive voltages these 1 to 5 neutron counts occurred? Surprising amounts of information can be gleaned from the tiniest scraps, but I do need to know the drive voltages used.
5 kV drive, 800 A (1000 gauss) - 1 count
9.8 kV, 750 A - 2 counts
12.5 kV, 700 A - 2 counts
12.5 kV, 800 A - 3 counts
14 kV, 1000 A - 1 count, loss of device

That's at about 13,000 neutrons (26,000 fusions) per count, over what looks like maybe a quarter of a millisecond or less in the case with 3 counts.
Add to those numbers- from Bussard's Valencia paper:
[EDIT- added link]

http://www.askmar.com/ConferenceNotes/2 ... 0Paper.pdf

The MPG machines obtained 10,000 to 100,000 fusions per second at 30,000 drive volts and 70-100 Gauss. (actual ion energy was much below this(?) and ion - neutral collisions were dominate).

PZL X-1 obtained 1 million fusions per second at 300 volts and 3500 Gauss.

WB4 obtained ~ 1 million fusions per second at conditions similar to WB6

(WB 6 neutron counts were equivalent to almost 1 billion fusions per second)

I don't know how these reported results can be fitted into a B- field strength, drive voltage, size , recirculation efficiency, ion density, ion/ neutral ratios, etc relationship . Presumably there is much more unpublished information about the plasma conditions, etc. that helps to flesh this out. Also presumably, the WB7 results expanded the information of B-field strength relationships vs different drive energies (in the same machine)- assuming they varied the B-field strength to a greater extent than WB6 and pushed the drive voltages higher while avoiding the short that ended WB6's life. If nothing else I assume they ran many more tests improving the confidence interval and obtained plasma measurements with more reliable methods. Dr Nebel has mentioned here that they used a different measurement method that confirmed some of the earlier but more uncertain measurements.


Dan Tibbets
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chrismb
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Post by chrismb »

D Tibbets wrote: WB4 obtained ~ 1 million fusions per second at conditions similar to WB6

(WB 6 neutron counts were equivalent to almost 1 billion fusions per second)
Careful, now. This half-implies that these things ran for a second. They may have produced a pulse of neutrons whose instantaneous rate was as you say, but if (for example) you compared that with DPF at 1E12 in 20E-9 secs, that'd give you a rate per second heading towards nothing less than ITER's hoped-for rate!

I do not warm to the argument that these reached 'steady-state' during their pulse just because an ion had the chance to run across the chamber a few thousand times. Remember that the 'dwell' time for an ion to achieve an 'average' fuse is many hours, not milliseconds, so the conception that this is 'steady-state fusion, just for a moment' seems misguided to me, notwithstanding the remaining question of what is the actual fraction of that neutron emission due to wall-bombardment.

It's an argument you hear pitched for tokamaks as well, the notion that they're producing some huge over-unity rate. JET runs for 'several' seconds and has reached some 80% for a couple of seconds, but hardly qualifies as 'steady state' as is implied in many press briefs. So if tokamaks can't claim this for a few seconds, then Polywell surely can't for milliseconds.

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Post by MSimon »

I do not warm to the argument that these reached 'steady-state' during their pulse just because an ion had the chance to run across the chamber a few thousand times. Remember that the 'dwell' time for an ion to achieve an 'average' fuse is many hours, not milliseconds, so the conception that this is 'steady-state fusion, just for a moment' seems misguided to me, notwithstanding the remaining question of what is the actual fraction of that neutron emission due to wall-bombardment.
chris,

Where do your numbers come from? From what I gather 60 collisions per fusion. At 1,000 transits per collision (beam beam) the average fusion happens in well under 1 second even in large machines. At 10,000 transit per collision you are approaching 1 second.

So where are the hours of dwell time?

And what does all this have to do with the rate of fusion - which is one of the critical factors? It matters not if the "average" fusion takes an hour as long as the rate of fusion is sufficient.

OTOH I do agree that continuous operation - seconds to minutes - is very important. There may be things happening on a seconds time scale that will help or hurt.
Engineering is the art of making what you want from what you can get at a profit.

chrismb
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Post by chrismb »

MSimon wrote: chris,

Where do your numbers come from? From what I gather 60 collisions per fusion. At 1,000 transits per collision (beam beam) the average fusion happens in well under 1 second even in large machines. At 10,000 transit per collision you are approaching 1 second.

So where are the hours of dwell time?
viewtopic.php?p=21852#21852

D Tibbets
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Post by D Tibbets »

chrismb wrote:
D Tibbets wrote: WB4 obtained ~ 1 million fusions per second at conditions similar to WB6

(WB 6 neutron counts were equivalent to almost 1 billion fusions per second)
Careful, now. This half-implies that these things ran for a second. They may have produced a pulse of neutrons whose instantaneous rate was as you say, but if (for example) you compared that with DPF at 1E12 in 20E-9 secs, that'd give you a rate per second heading towards nothing less than ITER's hoped-for rate!

I do not warm to the argument that these reached 'steady-state' during their pulse just because an ion had the chance to run across the chamber a few thousand times. Remember that the 'dwell' time for an ion to achieve an 'average' fuse is many hours, not milliseconds, so the conception that this is 'steady-state fusion, just for a moment' seems misguided to me, notwithstanding the remaining question of what is the actual fraction of that neutron emission due to wall-bombardment.

It's an argument you hear pitched for tokamaks as well, the notion that they're producing some huge over-unity rate. JET runs for 'several' seconds and has reached some 80% for a couple of seconds, but hardly qualifies as 'steady state' as is implied in many press briefs. So if tokamaks can't claim this for a few seconds, then Polywell surely can't for milliseconds.
OK, to be more acurate, the neutron production rates in these machines reportedly were so many neutron counts per run, which lasted some fraction (at least in WB6) of a millisecond. Based on a counting efficiency of 1 neutron detected out of ~ 26,000 neutrons produced(a number I have seen in these forums). A small percentage of the reactor was covered by the sensing neutron detector and the detector only responded to perhaps 1 neutron out of a thousand hitting it. This then multiplied by a running time to be equivilant to one second gives neutrons per second (or with D-D, fusions per second =2 X neutrons per second)This gives a apples to apples comparison with other machines. In this case it does indeed assume the Polywell could opperate in steady state over these timeframes (or very rapid pulses with minimal down time between pulses).

The time frame for a specific deuterium ion to fuse, based on the mean free path and the crosssection may be billions of meters, with your assumptions. When I (tried) to work through this in another thread, my impression was that this was reasonable from the realative perspective of a single ion, but was misleading. Again, an example is the Sun- a single hydrogen ion will bounce around in the core for ~ 8 billion years (how many meters of travel does that represent?) before it has a 50% chance of fusing. Yet because of the density/ numbers of hydrogen atoms in the Sun's core (and the volume) the energy output is ...er... large.The actual fusion rate for the system needs more information- ie the density.

Also, your numbers (I believe) relate to random motions in a thermalized plasma without any convergence (central focus) at all. Even a modest focus should change these numbers by a large amount. With a very tight focus (impossibly perfect focus) the mean free path could be no longer than the radius of the machine. *

* I wonder if Dr. Nebel took this into account when he claimed that alpha particles produced in a Polywell would transit ~ 1000 times before escaping through a cusp, while not losing much kinetic energy- ie the mean free path would be long enough that there would not be much transfer of energy between the alpha particles and fuel ions. With the alpha particles greater kinetic energy thier motions may be dominated by the magnetic fields as opposed to the electrostatic forces that dominates the fuel ion motions. I don't know how/if that changes the dynamics and convergence of the fuel ions compared to the alphas. Assuming some convergence and ion-ion collisions dominating the fusion process most of the alphas would be created near the center and initially have faily radial trajectories.
If there is too much focus the alphas may upscatter the fuel ions too much, or perhaps this would shift the average speeds of the ions in a controlable way, and increase the ion speeds in a benificial way- the alphas would be feeding energy back into the system so that input power could be decreased. Or perhaps it would compromise ion containment, or mono energetic electron dynamics, or ................

For a simple cluster of magnetic donuts and electrodes, things sure do become complicated fast.

Dan Tibbets
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MSimon
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Post by MSimon »

chrismb wrote:
MSimon wrote: chris,

Where do your numbers come from? From what I gather 60 collisions per fusion. At 1,000 transits per collision (beam beam) the average fusion happens in well under 1 second even in large machines. At 10,000 transit per collision you are approaching 1 second.

So where are the hours of dwell time?
viewtopic.php?p=21852#21852
Could you finish of the calculation and give me a power rate for your calculations? Just as a cross check.

In any case the "average residence time" is of no concern if the fusion rate is high enough and the losses low enough.

Generally chris I find your calculations about 6 to 12 orders of magnitude on the side of impossibility. It would be nice for cross checking if you rolled your numbers out like this:

F = ma

m = 2 kg
a = 10 m/sec^2

F = 20 newtons

Spell everything out.
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chrismb
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Post by chrismb »

MSimon wrote: Could you finish of the calculation and give me a power rate for your calculations? Just as a cross check.
That calc is just looking at a single ion. Say many ions are participating and recirculating and I'll give you a figure for total power out. It'd simply be;

N=no of ions
Q=fusion energy out per reaction
P=tot fusion power out
P=N/7000s x Q

(That'll take up reams for more complicated calcs!!)

In the case of the DD 1000A pulse example I ran further down that thread it'd be;

[ strike-through 2.5E16/7000 x 4.5MeV = 15uW]

edit: error in calc - see below.
Last edited by chrismb on Mon Aug 31, 2009 2:06 pm, edited 1 time in total.

MSimon
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Post by MSimon »

chrismb wrote:
MSimon wrote: Could you finish of the calculation and give me a power rate for your calculations? Just as a cross check.
That calc is just looking at a single ion. Say many ions are participating and recirculating and I'll give you a figure for total power out. It'd simply be;

N=no of ions
Q=fusion energy out per reaction
P=tot fusion power out
P=N/7000s x Q

(That'll take up reams for more complicated calcs!!)

In the case of the DD 1000A pulse example I ran further down that thread it'd be;

2.5E16/7000 x 4.5MeV = 15uW
You left out the numbers for N, Q, P, and P. And what is 2.5E16? Why is 7000 in there?

Why not run through all your calculations here and do it right this time?
Engineering is the art of making what you want from what you can get at a profit.

chrismb
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Post by chrismb »

MSimon wrote: You left out the numbers for N, Q, P, and P. And what is 2.5E16? Why is 7000 in there?

Why not run through all your calculations here and do it right this time?
Eh?

2.5E16 comes from the previous post that I have referenced. I can repeat endlessly in multiple places, or you can just try reading the links I provide.

MSimon
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Post by MSimon »

chrismb wrote:
MSimon wrote: You left out the numbers for N, Q, P, and P. And what is 2.5E16? Why is 7000 in there?

Why not run through all your calculations here and do it right this time?
Eh?

2.5E16 comes from the previous post that I have referenced. I can repeat endlessly in multiple places, or you can just try reading the links I provide.
Well I tried. You multiply a bunch of numbers to together and come up with an answer. I did that and I came up with 2. So right away there is a fundamental difference.
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chrismb
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Post by chrismb »

MSimon wrote: Well I tried. You multiply a bunch of numbers to together and come up with an answer. I did that and I came up with 2. So right away there is a fundamental difference.
Ah! Fair enough. I've played butter-fingers on the calculator. Yup, the calc comes out as 2.6W. Given that the pulse length assumed was 250E-6s, so that is a total output of 650uJ for the pulse.

Apologies for the confusion. Do check the arithmetic, that's why I pin it up line by line for these type of corrections.

Getting back to the question of how long is the residence time for an ion is before a fusion event, you see that if it were, say, 10,000 reciprocations instead of my 2.5 billion reciprocations, so that calculation would be x250,000 and so the fusion power out would have been 650kW. I'm pretty sure it wasn't, hence I'm pretty sure the residence time is a lot longer than 10,000 reciprocations both for theoretical and experimental reasons.

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