In other words, the National Ignition Facility hasn't achieved ignition yet.
If you can actually achieve ignition, then nobody will care about the megajoules needed to get it ignited. Because once you've got ignition, you can get an arbitrary amount of energy out.
But if you can't get ignition, well, then, that pesky 0.3% heating efficiency will still leave you a couple of orders of magnitude away from engineering breakeven.
Not really. You have to build larger, or more, power plants. So you have to make enough extra energy to sell to pay for plants.
~~ They've since had ignition: http://www.independentnews.com/news/article_792110c0-2c5b-11... ~~
[I'm positive that the ICF's predecessors also achieved ~~ignition~~ fusion on smaller scales.]
The real trick is that [0] you need to get out more than you put in (exceed break-even) [1] you need to be able to harness the energy produced by the ignition and [2] be able to do it over and over again, producing reliable power.
No. Notice how it is worded.
> "More importantly, Moses said, the mechanism that generated the powerful energy burst appeared to be the self-sustaining thermonuclear fusion process that defines ignition."
In other words, they did not achieve ignition. They achieved something that is necessary to get ignition. Specifically, alpha heating.
This is another important step on the road to ignition. It is not, however, ignition itself.
Why do you think the title of the article says "Marks Progress Toward Ignition," rather than "Finally Achieves Ignition?"
> the amount of energy released through the fusion reaction exceeded the amount of energy being absorbed by the fuel
As soon as I saw that, I immediately understood that they're nowhere near breakeven -- much less power generation.
Incidentally when I went to see JET (it's up the road from me, not that far from Oxford) the scale of the thing was enormous. They mentioned that they'd had been able to sustain plasma for 600 seconds. I've got some pictures up[2] on flickr.
[1] - http://www.i15.p.lodz.pl/strony/EIC/ne/future_2_1.html
[2] - http://www.flickr.com/photos/z3r0kl3w/sets/72157623979315835...
One of my favorite stories is the disruption. This happens when things don't go just right, and all the plasma with its energy squirts onto one spot. This typically puts the equipment in jeopardy. People try to prevent it, but as they push the boundaries of what's been done, it's going to happen.
Keep in mind that there's only about as much mass in the entire chamber as in a few cubic centimeters of air; it's basically a vacuum. But what little there is is so hot, and there's so much energy wound up in the fields. When JET had a disruption, the entire machine, the largest tokamak in the world, LIFTED ITSELF OFF THE GROUND AND JUMPED A FEW FEET OVER.
Any good refs for this disruption situation?
[1] http://lhc-machine-outreach.web.cern.ch/lhc-machine-outreach...
[2] http://www.symmetrymagazine.org/article/december-2007/protec...
1.7 megajoules.
In comparison, the fusion power produced was a paltry 8 kilojoules, which they compare to the "energy required to form the plasma".
For this technology to be actually effective, there needs to be a multiplier of several thousand. As other commenters have mentioned, this is mostly just nuclear weapons development.
[1] http://www.physicstoday.org/daily_edition/politics_and_polic...