Search found 144 matches
- Mon Sep 22, 2008 5:50 pm
- Forum: News
- Topic: ITER Costs Double
- Replies: 34
- Views: 18779
Jmc: I should have clarified this, but my comments apply to the US market and structure. I am in favor of nuclear fission power and back in the 70s I used to do a fair amount of nuclear advocacy. Although most of what the anti-nuclear people said was fear mongering, the local group we had was actual...
- Sun Sep 21, 2008 6:40 pm
- Forum: News
- Topic: ITER Costs Double
- Replies: 34
- Views: 18779
Classicpenny: Back in the 1970s “nuclear optimists” predicted that nuclear power would comprise 20% of the US electrical market by 2000. Guess what. That happened. How can that be even if a lot of plants were cancelled and no new plants have been ordered since the 70s? The answer is that the project...
- Mon Sep 15, 2008 11:02 pm
- Forum: General
- Topic: Focus Fusion
- Replies: 7
- Views: 6511
- Thu Sep 11, 2008 8:29 pm
- Forum: News
- Topic: TOKAMAK Instabilities
- Replies: 25
- Views: 16505
2. Mass power density has to do with the mass of the structure, not the fuel. The cost of electricity is based on how much stuff it takes to produce a given amount of power. There are two primary drivers for the COE: the mass power density and recirculated power fraction. My point is that if ITER-li...
- Tue Sep 09, 2008 11:05 pm
- Forum: Fund-Raising
- Topic: T. Boone Pickens
- Replies: 31
- Views: 32480
I've had some contact with Mr. Pickens in the past. In the mid 80s, Phillips Petroleum was making some investments in fusion. Mr. Pickens, who is a corporate raider, decided that they had two much cash on hand and that their assets were larger than their stock price. Consequently, he tried to make a...
- Tue Sep 09, 2008 12:07 am
- Forum: News
- Topic: TOKAMAK Instabilities
- Replies: 25
- Views: 16505
Josh: I've heard those statements and I'm not convinced. I asked Najmabadi (who heads the ARES conceptual design program) how well they could do on mass power density with their most advanced designs, and the answer I gotwas a factor of 10 worse than an LWR. Put a picture of an LWR power core (to sc...
- Mon Sep 08, 2008 11:32 pm
- Forum: News
- Topic: TOKAMAK Instabilities
- Replies: 25
- Views: 16505
I have three questions for JMC: 1. If the mass power density of ITER is several hundred times worse than it is for a light water reactor power core (which it is), how do you expect to compete with them? Or with any other power source? 2. If all magnetic confinement D-T systems have inherently poor m...
Muon fusion was tried experimentally at Los Alamos in the 1980s. The targets weren't plasmas, but rather were cryogenic. The problem was that a muon couldn't induce enough fusions to make up for the energy required to make the muon (Q<1). I believe the person who ran the experiments was Steve Jones,...
- Thu Sep 04, 2008 6:35 pm
- Forum: Theory
- Topic: The question of scaling
- Replies: 42
- Views: 23401
I wouldn't recommend doing a lot of modelling of the arcing right now. We've been looking at it, and it's complicated. It's not just a Paschen breakdown to the chamber wall. However, rather than sticking my foot in my mouth (by saying something that's not correct) let me say that we don't understand...
- Thu Sep 04, 2008 12:51 am
- Forum: Theory
- Topic: The question of scaling
- Replies: 42
- Views: 23401
Art: Lower Hybrid drift modes have been reported in earlier cusp experiments (Dolan's paper has some references), but they haven't been looked for in Polywells. I think the earlier machines were line cusp devices. Krall has stated that it is consistent with the observed "Magrid" scaling, but I would...
- Wed Sep 03, 2008 4:35 pm
- Forum: Theory
- Topic: The question of scaling
- Replies: 42
- Views: 23401
Hanelp: The collisionless limit is actually where turbulence is the most likely to dominate. In fluids, for instance, viscosity is what damps turbulence. The drivers are anything nonlinear. In fluids, that's usually convection. In plasmas, there are many nonlinearities. Any nonlinearity will cascade...
- Tue Sep 02, 2008 9:56 pm
- Forum: Theory
- Topic: The question of scaling
- Replies: 42
- Views: 23401
Aero and TallDave: My comments were primarily to give you an idea of the nature of the beast. The problem is that in order to experimentally study scaling you need to vary one parameter at a time. That is virtually impossible to do in a plasma. Secondly, all of the profiles have to be self-similar. ...
- Tue Sep 02, 2008 5:41 pm
- Forum: Theory
- Topic: The question of scaling
- Replies: 42
- Views: 23401
Art: I have two favorite papers on Tokamak scaling. The first was by Taylor and Conner where they showed that all of the empirical tokamak scaling laws were inconsistent with any known plasma physics model. The second was a paper by Wayne Houlberg where he put the empirical tokamak scaling laws into...
- Fri Aug 29, 2008 4:49 pm
- Forum: Theory
- Topic: The question of scaling
- Replies: 42
- Views: 23401
Art's right on this. The output power scaling for the Polywell is essentially the same scaling as for any magnetic confinement machine. The real physics issue is the input power required to keep the Beta constant. This has to balance the losses. In other words, the issue is how good the confinement ...
- Fri Aug 29, 2008 4:37 pm
- Forum: News
- Topic: TOKAMAK Instabilities
- Replies: 25
- Views: 16505
Simon: I wouldn't put a lot of stock in this. The codes that Garabedian is using are inadequate, too. Among other things, they don't have plasma flow. I don't think that the ITER equilibria are a huge extrapolation from the equilibria in either JET or C-Mod. Those machines work pretty well, so I sus...