As MaWM indicated it's many ionized atoms (free nuclei and electrons) magnetically confined in a plasma. The plasma is loosing energy very rapidly due to phenomena like brehmsstrahlung and cyclotron radiation, while nuclei scatter more often than they fuse.
You can say just about the same for any complex and hard-to-solve technical or social challenge we as a society confront. Example: What's the holdup with solar energy? You got photons streaming in for free and lots of ways of harnessing them. What's the big deal?
Confinement time ala Larsen would apply to confinement approaches, inertial or magnetic. Confinement time does not seem to apply to any of the several beam - beam approaches (e.g. IEC). That is, there's no intention to do ignition; they are purely 'driven' schemes. - Not that IEC has shown any possibility of power production"..., AND for a long enough time.
Yes, but it's hard to imagine making a practical fusion reactor with ICF, in large part because of the required repetition rate. Ignition may be achieved at NIF (that alone will be extremely challenging), but those target shots will be at best once every couple weeks - that's a very long way from firing it at 5-10 Hz, which is what you want for a practical reactor. If you scale up the energy you can get away with less-frequent bursts of energy, but that's going in the direction of a nuclear bomb, not a reactor.The designs for the NIF - the National Ignition Facility are intended to "do ignition"
Jeff,Yes, but it's hard to imagine making a practical fusion reactor with ICF, in large part because of the required repetition rate.
Maybe these problems will eventually be solved, but probably not in our lifetimes.
Jeff,Yes, I know people are thinking about reactors - there are some interesting concepts, They have to be fired somehow into the reactor at 10 Hz, aimed with micron precision over meter distances, in a manner that doesn't ruin the ice.
You are wrong again here. We DO understand - not just in simulations - but from experiment whatAnd at this point we don't really even understand the requirements on an ignitable target, all we have are simulation predictions that (based on long history) will almost certainly turn out to be wrong in significant ways.
I assure you that they have not been. Particularly the target problem, which I am intimately involved with. We struggle to make one suitable target, and there is no one working in the field, knowledgeable about the process, who is seriously thinking about making them at 10 Hz - there are only wild, utterly untested concepts from outsiders. Fast ignition might relax some of the target constraints, but that's a concept in it's infancy - we don't even know yet how we'll deliver the spark energy to the implosion.ALL of your concerns HAVE been addressed.
You sound like a designer. This is very naive, because Halite/Centurion experiments used a multi-terrajoule driver (a bomb), not a megajoule laser - you can afford to be sloppy when you have so much energy available. There were other very key target differences, perhaps (?) you are aware of them. Those experiments demonstrated the basic concept, but cannot tell us whether or not NIF will succeed at it's mission - or how our concept of an ignitable target will evolve as we learn more. We know how to ignite a target with terrajoules, but not with megajoules except through simulations - and long experience shows that every time we make a leap forward, we discover how much important physics is missing from the simulations.You are wrong again here. We DO understand - not just in simulations - but from experiment what the requirements of an ignitable target are.
Jeff,You sound like a designer. This is very naive, because Halite/Centurion experiments used a multi-terrajoule driver (a bomb), not a megajoule laser - you can afford to be sloppy when you have so much energy available.
From the referenced Jason's report:If you are citing the Federation of American Scientists website - then you are NOT on the
"cutting edge" of the technology like those of us who are actually developing the software
and designs. [ Besides that JASON report is nearly 3 years out of date. ]
Care to comment? Did NIF implement any of the Jason report's recommendations?...5. What is the prospect for achieving ignition in 2010?
First attempts to achieve ignition on NIF are likely to take place in 2010 — this is an
important and valuable goal that has strongly focused the efforts of the NIF Program. The
scientific and technical challenges in such a complex activity suggest that success in the
early attempts at ignition in 2010, while possible, is unlikely. ....
Between this and your mildly amusing private messages, I think I am done discussing this with you. I will point out, however, that having worked in ICF/NIF target experiments at LLNL for the last 15 years, and having attended the Jason review as well as having made some of the material that was presented, I've never heard of you. Perhaps if we run into each other sometime, we can discuss further over coffee.For Heaven's sake - use your BRAIN!!!
I missed this, it must have been edited out. I don't care about the FAS site, the link was to the Jason report. You appear to not know who I am, either.If you are citing the Federation of American Scientists website - then you are NOT on the "cutting edge" of the technology like those of us who are actually developing the software and designs.