WB7.1 Contract Awarded March 3, 2009

[alexjrgreen]

In the scientific, academic, engineering and legal worlds, 'evidence' is a full disclosure of facts of what it known so that all questions can be answered by it, up to the state of the art.

A good ideal. Often disclosure is subject to a "need to know".

Evidence in a divorce case is usually only available to the judge and the lawyers. Commercial confidence is usually respected in engineering safety reviews.

Even published scientific papers have been known to lack sufficient information for an experiment to be repeated without significant trial and error.

[alexjrgreen]

If you mean, to begin able to extract direct electricity from a wide spectrum of particle energies - no

Would a betavoltaic battery qualify?

[93143]

You don't use screens to catch the alphas. You use plates, not necessarily concentric with the magrid (possibly almost radial). Solid surfaces. The trap grid is just for shaping the potential; ALL the alphas go screaming through at full speed, and THEN they start slowing down.

If an alpha hits a collector plate with a finite amount of energy, that energy is converted to heat, but if you design the system halfway intelligently, it's not all that difficult to recover a large majority of the energy as HVDC.

I've messed around with some half-baked plans that might not be all that bad with respect to efficiency. The idea is to use field shaping to guide the alphas to sections of the collector system that are at the correct potential. A number of plates separated by insulation might work reasonably well.

It's true that it might turn out to be too difficult, and it might even be better from a sputtering point of view to just let them all hit the outer wall at full speed and use a thermal cycle.

But the idea of direct conversion certainly shouldn't be dismissed out of hand as quickly as you did, and certainly not on the grounds you cited.

[chrismb]

The originally contested statement was

A polywell reactor, remember, generates electricity by direct conversion. This greatly reduces the amount of noise generated by the power plant (I am not aware of acoustic issues inside a polywell), as you dont need turbines, wont have cavitation or a lot of moving parts. A polywell powered sub can dump waste heat to the surrounding water.

which implies not only sole conversion to DC, but it is being done today with current Polywell reactors.

If you are arguing only for a modest electric-field reduction of particle energy prior to a thermal extraction, then I can go with that, sure. So we'll set the electric field extraction at ~2MeV (how does that sound?) which means that of the 2-5MeV and 6-10MeV spectral ranges, we'd recover maybe even 10% percent? I don't now what the illumination levels are in those spectra, perhaps there is a more accurate answer.

How transparent are these DC recovery grids?

[93143]

How transparent are these DC recovery grids?

They aren't transparent at all. Re-read my post, right above yours.

The originally contested statement... implies not only sole conversion to DC, but it is being done today with current Polywell reactors.

I think all of us know what he meant. Criticizing something like that just makes you come off like a nitpicker.

the 2-5MeV and 6-10MeV spectral ranges

The generally accepted reaction is p+11B -> 12C* -> 4He+8Be*+5.64MeV -> 3x4He+8.68MeV, with a probability of about 99.99% as far as I can determine (ie: Wikipedia doesn't mention any other major reaction, and I can't access journal articles from home). This means you get one alpha at 3.76MeV, and two more at an average of 2.46MeV, depending on what axis the 8Be blows itself apart along. Assuming a stationary start, the limits for the low-band alphas are ~70keV and 4.85MeV. Naturally the plasma temperature will modify these values somewhat.

I think I remember you posting a source that claimed something different, but I can't remember where.

What you might do is design the collectors to pick up the low-band alphas at a reasonable efficiency, using a significant number of surfaces separated by insulation gaps (which should rapidly pick up positive charge and act as 'bumps' in the potential, sort of like the standoffs on WB-6 and WB-7), with high-voltage repellers in the wide spaces between the collector plates to deflect the particle paths sideways into them. You could add magnets, mass-spectrometer-style, for extra fun if you can figure out how to work it... Just make sure you happen to have a surface in the system at 1.88MV to pick up the high-band alphas (which will have a very narrow spread) with minimum loss. That's my guess at what the system might be like... There was a thread about it, but it sort of fizzled without reaching a definite conclusion...

[KitemanSA]

I thought some one posted a link to a design for just such a direct conversion device.

I do recall such a link, but it was for a mono-energetic alpha converter as discussed by chrismb. The sourse was alpha decay of one of the heavies, one of the Actinides or maybe a Lanthanide.

[chrismb]

I think all of us know what he meant. Criticizing something like that just makes you come off like a nitpicker.

You and I, and many others, may know what was meant because we can put it in some sort of context of what we know already.

But there are many more who are now convinced that a working MegaWatt-producing Polywell is a foregone conclusion and is just a bit of engineering short of fusion power, if only those meanie, self-interested, oil-company-shareholding polticians would fund it.

It is these *sales-pitches* that are to blame, so it is more than nitpicking because there are some wholly unsubstantiated views on Polywell's future success now circulating.

Besides, this is a distraction to the original posting because my critique was of the suggestion of a 100% DC converter scheme, which WAS implied,

[Aero]

The sole source justification has been posted.

https://www.neco.navy.mil/synopsis_file ... 9R0024.pdf

It makes interesting reading if you're in to that sort of thing. The price seems low for a year long contract.

[KitemanSA]

Has anyone found the equivalent documents for the three earlier solicitations? That would give us a good idea of the total level of funding for this year.

[Chuck Connors]

Kiteman,

Searching on the 3 Contracts listed on the WB 7.1 from above-

N68936-09-C-0027 Awarded 2009 294,000
N00014-93-C-0224 Awarded 2005 249,000
N00014-96-C-0039 Awarded 2006 3,210,697
N68936-03-C-0031 Awarded 2003 4,994,197

This was just a quick google search- There is obviously more contract activity than just this- I didn't see the contract for WB 7, unless this was part of the 2003 award. A more thorough search of Talk-Polywell would likely turn up the answer.

[KitemanSA]

Thank you for your rapid response!
I am sorry, I was not clear. I meant to ask about the three earlier solicitations this fiscal year. There was one in early September and two more in late October. But your example has inspired me to see if I can find it.

[Billy Catringer]

The sole source justification has been posted.

https://www.neco.navy.mil/synopsis_file ... 9R0024.pdf

It makes interesting reading if you're in to that sort of thing. The price seems low for a year long contract.

The redactions leave us with some interesting holes to fill, not about dollar amounts and what have you, because they are relatively small. The real question is why?

[MSimon]

Thank you for your rapid response!
I am sorry, I was not clear. I meant to ask about the three earlier solicitations this fiscal year. There was one in early September and two more in late October. But your example has inspired me to see if I can find it.

I believe there is a link at IEC Fusion Tech. also some contract #s.

[Betruger]

The sole source justification has been posted.

https://www.neco.navy.mil/synopsis_file ... 9R0024.pdf

It makes interesting reading if you're in to that sort of thing. The price seems low for a year long contract.

The redactions leave us with some interesting holes to fill, not about dollar amounts and what have you, because they are relatively small. The real question is why?

Are you sure those are redactions? I can read some of them. They look more like bad scanning contrast.

[John Gallagher]

Charge can be collected from an electron beam that has a wide energy spectrum by a device that is a series of plates with a hole in the center to let the beam pass. Each plate is biased to collect a small part of the energy spectrum. The device I am familiar with was used on a CW free electron laser and was actually placed in the high voltage terminal of a pelletron (Van de Graaff) HV generator. From the perspective of the HV terminal it was an energy sink but since it alowed the charge to be recovered from the perspective of ground it was collecting about 400 KW!! I should have started by saying that the charge that was collected by this electron collector was sent out of the high voltage terminal in the form of an electron beam with a narow energy spectrum. This was sent through a wiggler in which part of its energy is turned into electromagnetic radiation. The result being a beam with a much wider energy spectrum. By the collection and recirculation of this beam the laser was able to recirculate an electron beam current of 200ma at about 2mev. The pelletron charging chains had only to supply the charge lost in the vacuum transport piping which was on the order of 400 micro amps. The energy extracted by the actual laser was replaced by the collector. It's all in the biasing.