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

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ladajo
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Post by ladajo »

mvanwink5 wrote:Ladajo,
The group got together already, so I strongly suspect that the determination to authorize 8.1 has been made. In fact, that is what I think, "merited continuation and expansion," meant, especially the expansion part. As infrequent as they get these guys together, I doubt there will be another meeting until reportable results from 8.1 are acquired.

I feel we are really lucky to get this level of insight, sketchy as it may be. Is it for sure we will see expenditures that are made for WB8.1?
Best regards
If they follow plan and precedent, I would expect they get together to review the full WB8 results before pressing on.

The only money publically talked about to date has been WB8 money.
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zbarlici
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Post by zbarlici »

If they go ahead with WB8.1, then we would know the device works. Is there any reason the beefer would not work with Pb11 if the 8.0 version has proven the machine works?

D Tibbets
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Post by D Tibbets »

zbarlici wrote:If they go ahead with WB8.1, then we would know the device works. Is there any reason the beefer would not work with Pb11 if the 8.0 version has proven the machine works?
Yes...

Physics issues: thermalization issues, Bremsstrulung issues, uncertainaty about direct conversion issues, etc.

Engineering issues: Vacuum issues, boron handling issues- it may form solid deposits on surfaces, direct conversion issues, arc discharge issues at higher voltages, etc.

It does seem encouraging though that P-B11 is apparently still a working goal as they gain further experimental knowledge about the system. This suggests that D-D fusion is an even more workable fallback goal. And secondly, that D-He3 fusion (using He3 from D-D fusion) may be an easier goal than P-B11 in situations where significantly lower neutron production is needed.

Dan Tibbets
To error is human... and I'm very human.

zbarlici
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Post by zbarlici »

I don't wanna sift thru the countless threads in the theory section, you're saying that D-He3 is less harmful than the PB11 ? Ok, what's the drawback, in layman's terms... :(

93143
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Post by 93143 »

No, D-³He is less neutronic than D-D. It is far more neutronic than p-¹¹B, especially in a Polywell where the primary neutronic side reactions for p-¹¹B are heavily suppressed.

choff
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Post by choff »

At some point in the process there has to be a go/no go decision on phase 3, a $250 million full scale 100MW device. That means maybe another year and a half to get the new e guns operational and ramp up the power supplies, then the 8.1 modify for hydrogen boron attempt.
CHoff

MSimon
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Post by MSimon »

93143 wrote:No, D-³He is less neutronic than D-D. It is far more neutronic than p-¹¹B, especially in a Polywell where the primary neutronic side reactions for p-¹¹B are heavily suppressed.
It hardly makes any difference in shielding. Especially given that the shield for D-D you have to reduce the flux by 1E10 vs pB&J @ 1E7. i.e. about a 30% reduction in shielding material.

Where it matters is SC winding lifetime. And there an increase of 1,000 is very significant. Lining the SCs with B10 and using MgB11 will also have considerable influence. I did a fair amount of preliminary work on that a few years back. The archives. Ugh.
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Post by MSimon »

Delay may not hurt too much give the rate SC technology is advancing.
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93143
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Post by 93143 »

What happened to the 1e8 reduction in neutronicity, cf. rnebel?

The main shielding requirement for p-¹¹B was for the gammas, last I checked... and the gammas are a doozy, assuming they show up...

hanelyp
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Post by hanelyp »

As I recall, the prime neutron producing side reaction from p-¹¹B is fusion alphas reacting with ¹¹B, greatly suppressed by quickly removing the fusion alphas. A big win for selectively leaky containment.

MSimon
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Post by MSimon »

93143 wrote:What happened to the 1e8 reduction in neutronicity, cf. rnebel?

The main shielding requirement for p-¹¹B was for the gammas, last I checked... and the gammas are a doozy, assuming they show up...
If you go back and look it was only 1E3. Watch the Google video again.
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MSimon
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Post by MSimon »

B10 + n = 500 KeV gamma + other stuff. The "500 KeV" is not exact but it is in the ball park. You can look it up. But that is just for shielding. I don't recall other gammas from pB11 or side reactions. It is all in the archives though and I'm getting busy so I'm not going to redo the research or look it up.
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MSimon
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Post by MSimon »

93143 wrote:What happened to the 1e8 reduction in neutronicity, cf. rnebel?

The main shielding requirement for p-¹¹B was for the gammas, last I checked... and the gammas are a doozy, assuming they show up...
I believe Nebel was making assumptions. I, like any good engineer with unknowns, assumed worst case.
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 »

In the Google talk, are you sure Bussard was not referring to the D-He3 diluted reaction when he mentioned the 10^-3 neutrogenicity? The ~ 10^-8 number for P-B11 has been mentioned multiple times, though I'm uncertain of the source.

As far as a 500 KeV gamma that would not be much of a shielding challenge.

It seems I recall the C12 excited isomer, instead of spitting out an alpha, it spits out an ~ 15MeV gamma, and a stable C12 in ~ 1 reaction out of ~ 10,000.

Dan Tibbets
To error is human... and I'm very human.

MSimon
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Post by MSimon »

D Tibbets wrote:In the Google talk, are you sure Bussard was not referring to the D-He3 diluted reaction when he mentioned the 10^-3 neutrogenicity? The ~ 10^-8 number for P-B11 has been mentioned multiple times, though I'm uncertain of the source.

As far as a 500 KeV gamma that would not be much of a shielding challenge.

It seems I recall the C12 excited isomer, instead of spitting out an alpha, it spits out an ~ 15MeV gamma, and a stable C12 in ~ 1 reaction out of ~ 10,000.

Dan Tibbets
The 1,000 times less n flux was for pB11.

I don't recall the C12 reaction you mentioned but a lot has faded from not working on it every day.
Engineering is the art of making what you want from what you can get at a profit.

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