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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Roger
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Post by Roger »

chrismb wrote: So, no, personally I'm not really interested in validating one against the other....
I know that. But then you're not Dr Nebel either. Who WAS trying to validate.
I like the p-B11 resonance peak at 50 KV acceleration. In2 years we'll know.

MSimon
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Post by MSimon »

Roger wrote:
chrismb wrote: So, no, personally I'm not really interested in validating one against the other....
I know that. But then you're not Dr Nebel either. Who WAS trying to validate.
Or the Navy which paid for the validation.
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 »

93143 wrote:
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.
I'll assume that their were no significant changes in specifications between WB-6 and Wb-7. I'll assume that WB-7 got the same results, except for the 14Kv run.

I wonder if Dr Nebel ran WB-7 @ 14 kV, 1000 A. And did he get 4 counts? (100k+ fusions)
I like the p-B11 resonance peak at 50 KV acceleration. In2 years we'll know.

chrismb
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Post by chrismb »

93143 wrote:
chrismb wrote:Is there any indication over what drive voltages these 1 to 5 neutron counts occurred?
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
So, presuming this is DD we're talking about here, the 'reactivity ratios' provide the following insight;

If the reactions were all fast-slow and all driven by the drive voltage, then the ratio of results should look like:
9.8kV:5kV = x2175 (actual x2)
12.5kV:9.8kV = x8 (actual x1.5)

If the reactions were all fast-fast and all driven by the drive voltage, then the ratio of results should look like:
9.8kV:5kV = x11 (actual x2)
12.5kV:9.8kV = x2 (actual x1.5)

So it is clearly looking more like a fast-fast scenario!

Before I fling cartwheels, however, if these are statistically significant then I will want to dwell on why there are 'so many' neutrons emitted at 5kV. 'So many' hardly seems the right term to use with one count, but this *is* in the right direction to convince me.

Was this with ion gun(s), or just by ambient ionisation?

KitemanSA
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Post by KitemanSA »

Neutral puff gas with in-situ ionization.

chrismb
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Post by chrismb »

So, do we know how long the 'functional operating period' was in these tests?

93143
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Post by 93143 »

Well, as I said, from the graph of the 3-count test it looks like all three counts happened in the space of less than a quarter of a millisecond. IIRC they were all sub-millisecond pulses, typically 0.4 ms or less.

chrismb
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Post by chrismb »

Do we know how the in-chamber [actual] drive potential was measured?

The flat-ness of the results you've written 'concerns' me [makes me think hard]. On the face of it, it just seems too flat for a "drive-voltage versus fusion" function and may need to be explained by either a) differences in the length of the actual operating [fusing] times, or b) higher potentials (due to inductive effects) within the chamber than are actually fed and measured as going into the device.

(My other basic concern is the efficiency; is this meant to work out as 65Mneutrons/sec (40uW) for 4MW input, of the order of 1E-11 efficiency at 5kV (1E-10 at 12.5kV) cf. a fusor at around the 1E-8 efficiency, but we can 'car-park' that for now and firstly look at whether fast-fast is going on, which is more of a noteworthy matter.)

I would, personally, describe these results as "nuanced"!!!

93143
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Post by 93143 »

Remember that the drive voltage and the coil current are unrelated. It looks like external current was much less than 100 A at the start of the fusion pulse. It's just starting a rapid rise to ~4000 A, labeled "Paschen arcing", so it's hard to tell...

Oh, wait - there's a graph of "emitter current" that peaks at 40 A. So there you go.

Also, the fusion rate calculates out to about 3e8 per second (this is all for the 3-count test). Bussard seemed to think this was close enough to 1e9, order-of-magnitude-wise, that he just claimed ~1e9 fusions per second... of course, the confidence interval is pretty wide...

Also note that the coil current (and thus the magnetic field, and thus the plasma density) was varied between tests...

It is stated that well depth was about 80% of drive voltage. I'm not sure how this was determined.

It occurs to me that due to the rather crude experimental setup, the pulse width may, in fact, have been significantly larger at lower applied voltages, due to things not going south quite as fast...

TallDave
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Post by TallDave »

So, do we know how long the 'functional operating period' was in these tests?
Well, keep in mind, the device is only at beta=1 for a very short time. The "pulses" sweep through beta=1, with maximum fusion presumably occuring at the peak density -- which would be the normal state of affairs during the "operating period" of a cooled, non-pulsed machine.

vankirkc
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Post by vankirkc »

Quickly stepping back to the original topic...

40m is a lot of money to just about anyone except the government. I don't see a commercial party investing that much in this technology when it is at a stage where its feasibility is substantially in doubt.

In another thread it was mentioned that debate on the merits of the technology had reached the limits of what is possible without data. Obviously we are without data because the one funded Polywell experiment is a closely held secret of the U.S. Navy. Perhaps what is needed is not a net power WB-100 variant, but a smaller scale device on the scale of what EMC is working on.

A two million dollar investment is still a tall order given the state of the science on this thing, but I think it's far and away more likely to be found than someone with 40 million to burn, and it would have much lower risk for everyone involved.

The only other suggestion I would make is that to sell this idea to the private sector, it probably would be a good idea to crystalize the design and physics into a business plan document. Perhaps this is something you are already working on. While this site has been an interesting read and a good place to learn about the technology, it is neither concise nor particularly well organized for the layman, as a potential investor is likely to be.

MSimon
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Post by MSimon »

vankirkc,

You would be surprised at what kind of loose change is out there for blue sky work.

Tri Alpha has something like $5 million in hand with a promise of $35 million more if it looks promising. All private money.
Engineering is the art of making what you want from what you can get at a profit.

MSimon
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Post by MSimon »

While this site has been an interesting read and a good place to learn about the technology, it is neither concise nor particularly well organized for the layman, as a potential investor is likely to be.
That is what the text and sidebar links at

http://iecfusiontech.blogspot.com/

are for.
Engineering is the art of making what you want from what you can get at a profit.

TallDave
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Post by TallDave »

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.

vankirkc
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Post by vankirkc »

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.

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