ladajo wrote:Are you or have employed by John Slough or Helion? Have you been directly involved with the work they are doing? Have you at least been in the lab and talked serious science with the PI?
I too "have knowledge that I don't share here."
I say this because I DO know first hand that others of equal or greater stature do not see him the way that you do.
I guess it depends on who you talk to. This is academia in a highly competitive and very complicated field full of people that are very entitled to their opinion. One of my friends is the senior scientist at ITER, probably the most mainstream fusion effort you can find. Yet, ITER is probably among the most harshly criticized projects in the field (due to the delays and cost overruns) and his person is most likely not uncontroversial among ITER's detractors.
Finally, I want to add that clearly not everyone around Slough has a low opinion of him or his work (personally I know more people that like and respect him than the other way round). In example Charles Grossnickle, who lead the other (steady state/He3) FRC effort at the UW before his lab ran out of funding, always talked about Slough and his research with lots of respect and as I mentioned earlier Michl Binderbauer from TAE also seemed to be rather fond of him.
ladajo wrote:I personally have not spoken or interacted directly with any of the core Helion team.
I think you should do that, when you have the opportunity. It would be a good idea to actually get some first hand information prior to forming an opinion and then expressing that opinion rather viciously on a public forum. You know that you can actually hurt peoples serious and honest efforts this way.
ladajo wrote:You have missed the point. Slough is a high density plasma guy. What I have been asking you is who are the other high end plasma guys? Why are there not any?
Kirtley is not a high density plasma guy, he is a plasma jet guy, and did not spend that long doing it. He is not considered a top tier plasma scientist in the community.
You asked for careers outside of MSNW, I showed you careers outside of MSNW. So it is you who missed my point. David Kirtley is most of all an engineer with a lot of experience of managing projects similar to this, which is one reason why he is holding the position of CEO at Helion.
ladajo wrote:So again, if Slough is at the front of the argument for succeeding in compact plasma based fusion, why is there not another top tier guy on his team? One would think that folks would be lining up.
Money? High end plasma physics people cost a lot of money and Helion have not exactly been blessed with tons of funding until very recently. Helion is hiring right now but I do not know what kind of people they are looking for. From what I understand most of their remaining issues are more related to systems engineering than the fundamental plasma science.
ladajo wrote:These guys do talk to each other all the time, and they do know who is doing what and how. There is an completely formed and functioning layer under these public marketing displays that you are apparently unaware of where the senior folks in the community are constantly having interaction. You can almost call it the unofficial "Plasma Fusion Science Board". And yes, I do know and talk to folks in that circle.
Once again, you are making assumptions about my person and what or who I know or don't know.
D Tibbets wrote:Art Carlson once tried to label Eric Learner's work as bad science. He eventually abandoned the effort for what ever reason. LLP has since demonstrated significant results and insights. That does not mean his efforts will suceed from a physics standpoint or engineering standpoint, but it is promising.
I have a lot of respect for Art. He is/was one of the more knowledgeable people to post on this board. I cant remember what exactly he said about LPP. I do understand his skepticism however. I find them rather likeable (maybe a bit quirky, but who isn't?) and I am watching them with a lot of interest because of their open approach but I am still not convinced that their efforts will go anywhere in the end. From my understanding a big problem with their concept is that it does not scale well. If they can't make it work at the current scale with enough Q to be feasible, they will be stuck. And a lot of that depends on whether they can get the direct conversion to work.
I once again find it worth pointing out that Art originally was also highly skeptical about Helion and Slough but changed his mind after visiting their lab. So if people don't take it from me (because I am just a software engineer), you should at least listen to Art.
D Tibbets wrote:35 KeV seems low, for D-He3, I would expect target temperatures closer to ~ 80 KeV. 35 KeV would be good for D-T, poor for D-D, but bordering on dismal for D-He3 (based on viewing cross section grafts and corresponding Bremsstruhlung rates. Bussard pointed out in one paper that about 5 KeV was the absolute minimum for D-T fusion output yield to exceed Bremsstruhlung losses, even with assumed perfect particle confinement. Other fuels have higher minimal (and for that matter maximum) temperatures for the window where fusion output can exceed Bremsstruhlung losses.
I honestly don't have a good answer for you, right now. It may be that they use the 35keV number only as a requirement for their upcoming break even experiment and not for the actual economic power generating reactor. I cant say that with confidence right now, however.
D Tibbets wrote:The comment about persueing D-T as an admission of inferiority is an uncertain assessment.
I did not mean it that way. I meant that it is an easier goal to reach and I know that EMC2 is going to do that for the first version of the Polywell. Where they will go from that remains to be seen and probably depends on the results of their experiments. My main point was that due to the geometry and layout of the Helion reactor, it is comparably well suited for D+T since it is comparably easy to service. I find it worth mentioning that they already have 5 keV, which as you say is enough heating power for D+T (even though it may be the bare minimum).
This would theoretically allow Helion to go with D+T as a fallback for an actual commercial reactor, not just for an experimental reactor.
I may be wrong (please correct me if I am), but I don't believe the Polywell is as well suited for D+T. LPP's DPF certainly is not. TAE's reactor is much more complex with lots of expensive parts near the central "burn" chamber. So I assume (but may be wrong) that it won't work as well for D+T.
D Tibbets wrote:For aneutronic fusion the Polywell has some tricks that may benefit it. I don't know how the FRC handles these issues (as well). Spherical convergence, and energy distribution of electrons associated with an electrostatic potential well are significant advantages. Could some of these electrostatic considerations be applied to FRC?
I agree with the advantages of the Polywell for PB11. But then, we also have TAE who are convinced that their FRC machine will work well with PB11. Their design is aiming for a steady state with long confinement times, measured in minutes, however.
Helion's reactor has some similarities to TAEs design, but because they are less ambitious and more pragmatic, they have lower requirements that are easier to meet. This IMHO gives them a lot of credibility, but your own impression may differ. Anyway, I don't think I came over as talking down on Dr Park or the Polywell or anyone for that matter. If I did, it was not on purpose. I simply think that with the current funding situation and goals set for each effort that I am watching, Helion has IMHO the best shot at being first. The future is hard to predict and I might very well be wrong.
I did not expect this to turn into a mud fight over the reputations of the people involved, which I honestly find highly inappropriate.
I really like Dan's factual argumentation (thanks, Dan) and will try to get some answers for him, if I have the chance.