The recent news seems to have polarised the debate in a not very helpful way. There is an issue of whether to "trust" Rick and his statements about EMC2 or not.
FWIW here is my opinion. I think it will be held by many here, but I am not seeing it widely posted.
Rick has never made extravagant claims for Polywell. In his latest clarification he has said that past results indicate that further testing is needed to determine feasibility. that is indeed nuanced, and says neither that there are show stoppers nor that it will work.
He has said that he would not hide show stoppers. I see no reason to disbelieve this.
Unlike many other secretive concerns, EMC2 is not claiming anything against laws of physics, or even far outside what is currently known to be possible. True, there is a big question mark about whether bremsstrahlung will stop use of "advanced fuels" in polywell reactors, even if they otherwise work. And without these neutron flux probably is much more problematic than it would be for ITER, say, because of all those exposed magnet housings and maybe other issues. But engineering problems of that sort do not normally prevent fusion resecrh and a known beta ~ 10 smallish device would create great interest regardless even if it turned out not to be commercially viable as a power source.
Nebel would appear to be a decent cautious scientist, wanting the truth more than (or at least as much as) self-agrandisement. He no doubt feels loyalty to EMC2 and does not want them all to lose their jobs, so may explore every avenue before admitting Polywell does not work, if that is the result. He has a clear plan of investigation which will lead to better (though if positive still not definitive) results.
And results so far have been peer reviewed by credible independent scientists.
This set of facts is not true of BLP, EEstor, or any of the other vapourware companies with which EMC2 has been compared.
That does not mean that Polywell is going to work, or that the results so far are wonderful. It does mean they are good enough not to rule out success. Even then, other things may well rule out success, but that is another story.
As for secrecy I think Polywell has a case based on its own interests, since there is no IP protection. I suspect also that the Navy will have an effective policy of denying FOIA requests whenever this is humanly possible, on whatever excuse can be found, and that if Rick wants continued funding he would be well advised to be helpful to the Navy in this respect.
I think the call for money to leapfrog current results and do some design work is mildly positive. If things were looking bad so far Rick would probably be taking a different approach.
None of which means that Polywell with advanced fuels seems likely. But room for lots of speculative hope, and a decent chance that interesting beta can be obtained at least for DT.
Still it is a shame that information flow from current tests may be very sparse.
Best wishes, Tom
A nuanced approach to EMC2
"We will know in 18 months to 2 years" That is quite definitive and not a quibbling statement.He has a clear plan of investigation which will lead to better (though maybe still not definitive) results.
Trusting memory, and to paraphrase, Rick has written that "we," meaning EMC2, will know in 18 months to 2 years. He has also written that WB-8 was instigated as a result of issues raised by peer review of WB-7. My question is this. What issues? I guess they can be resolved using a sub-scale model and don't require p-B11. Confinement issues? Transport issues? Scaling issues? Fueling issues? Poisoning issues? Your guess issues?
Aero
That sounds about right Tom.
Aero -- I think people may be misinterpreting Rick's statement about WB-8. Bussard wanted to jump straight to a 100MW machine, but that was very optimistic when they still had issues like the nubs to resolve (which you can see they are addressing in WB-8) and the only B scaling was from small machines (and Bussard knew he didn't have long to live, so it's hard to blame him for wanting to hurry). Also, WB-8.1 is intended to burn p-B11, which has never been done before in a device like this. It's not surprising the peer review recommended a .8T ~500W machine.
An intermediate size makes a lot of sense, a point that was being made by some here long before the WB-7 contract. After WB-8 is up and running, EMC2 should know whether a reactor attempt is justified.
Aero -- I think people may be misinterpreting Rick's statement about WB-8. Bussard wanted to jump straight to a 100MW machine, but that was very optimistic when they still had issues like the nubs to resolve (which you can see they are addressing in WB-8) and the only B scaling was from small machines (and Bussard knew he didn't have long to live, so it's hard to blame him for wanting to hurry). Also, WB-8.1 is intended to burn p-B11, which has never been done before in a device like this. It's not surprising the peer review recommended a .8T ~500W machine.
An intermediate size makes a lot of sense, a point that was being made by some here long before the WB-7 contract. After WB-8 is up and running, EMC2 should know whether a reactor attempt is justified.
n*kBolt*Te = B**2/(2*mu0) and B^.25 loss scaling? Or not so much? Hopefully we'll know soon...
How or from where did you arrive at the ~500W?It's not surprising the peer review recommended a .8T ~500W machine.
An intermediate size makes a lot of sense,
You are right in that it is not surprising that peer review recommended, and EMC2 welcomed a smaller than full sized machine. But what can be done with a small machine that could not be done with a larger one? Nothing. Granted there are unresolved issues, hence for political reasons, to avoid looking stupid, it is much safer to test using a machine that cannot possibly work anyway, its too small. What would have been the buzz if they had contracted for a full sized machine to test with? And what would have been the negative impact if it didn't "work?" I suspect that the main driver for another sub-scale machine was to avoid spending political capital by all concerned and that is a good reason in my book.
My question stands unanswered, " What issues? I guess they can be resolved using a sub-scale model and don't require p-B11. Confinement issues? Transport issues? Scaling issues? Fueling issues? Poisoning issues? Your guess issues?" Certainly more than the "nub" issue.
Is it scaling issues as many here have debated? Whatever they are, they are clearly not related to p-B11 issues.
Aero
Rounding error?KitemanSA wrote:By other posted analyses, WB-6 = 0.6mW.Aero wrote: How or from where did you arrive at the ~500W?
WB8 has 8 x B field and 5/3 x size.
.0006 X 8^4 x (5/3)^3 = 11W.
Dang, how did you get 500W?
Engineering is the art of making what you want from what you can get at a profit.
5/3 radius increase. Where did you get that and please don't say from the picture on EMC2's website.MSimon wrote:Rounding error?KitemanSA wrote:By other posted analyses, WB-6 = 0.6mW.Aero wrote: How or from where did you arrive at the ~500W?
WB8 has 8 x B field and 5/3 x size.
.0006 X 8^4 x (5/3)^3 = 11W.
Dang, how did you get 500W?
@Betruger - It is true that a smaller Polywell fusion reactor machine should be safer to work near. But as I noted above, if asked, and given that there were unanswered issues, I would have concurred with the decision to build a sub scale machine with which to complete testing. What's your point?
Aero
-
CaptainBeowulf
- Posts: 498
- Joined: Sat Nov 07, 2009 12:35 am
I largely agree with Tom Clarke's analysis.
IMO it's almost certain that WB-8 and the now-discussed WB-9 were/are needed to study various issues before a full scale reactor can be attempted. The fact that they are proceeding with the work indicates that no show-stoppers have been found, but they can't be sure that no show-stoppers will crop up until the further testing on WB-8 and WB-9. That's legitimate science.
However, unfortunately everything else is speculation until we see the data. I can understand why they don't want to release data right now, for reasons listed by others above and in other threads.
The trolling/troll-feeding going on in other threads is kind of amusing to me, but really adds nothing to our understanding of this.
Maybe Famulus will come up with something interesting.
IMO it's almost certain that WB-8 and the now-discussed WB-9 were/are needed to study various issues before a full scale reactor can be attempted. The fact that they are proceeding with the work indicates that no show-stoppers have been found, but they can't be sure that no show-stoppers will crop up until the further testing on WB-8 and WB-9. That's legitimate science.
However, unfortunately everything else is speculation until we see the data. I can understand why they don't want to release data right now, for reasons listed by others above and in other threads.
The trolling/troll-feeding going on in other threads is kind of amusing to me, but really adds nothing to our understanding of this.
Maybe Famulus will come up with something interesting.
Well, lets see:MSimon wrote:Rounding error?KitemanSA wrote:By other posted analyses, WB-6 = 0.6mW.Aero wrote: How or from where did you arrive at the ~500W?
WB8 has 8 x B field and 5/3 x size.
.0006 X 8^4 x (5/3)^3 = 11W.
Dang, how did you get 500W?
.0006 X 8^4 x (2)^3 = 19W.
.0010 X 8^4 x (2)^3 = 33W.
.001 X 10^4 x (2)^3 = 80W.
Hmmm, what else can be rounded?
I just don't understand how you can say that when you don't know the data.Aero wrote: @Betruger - It is true that a smaller Polywell fusion reactor machine should be safer to work near. But as I noted above, if asked, and given that there were unanswered issues, I would have concurred with the decision to build a sub scale machine with which to complete testing. What's your point?