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Nuclear Fusion Real Soon Now

Posted by michael on from the you-betcha dept.

Mr. A. Coward writes "Researchers at the National Ignition Facility are attempting to produce nuclear fusion. They'll focus 192 amplified lasers on a pellet of frozen hydrogen. 'NIF experiments will be the first to create fusion that gives off more energy than it takes in.' That will have to be quite a bit, since it will take 500 trillion watts to ignite the pellet in the first place. The facility has been plagued with delays, and so far only 4 of the 192 lasers have been completed. Researchers believe they will first achieve fusion sometime around 2014."

9 of 604 comments (clear)

  1. Re:Researchers? by AKnightCowboy · · Score: 5, Informative
    Come on, this is ridiculous. Fusion is impossible. If it was possible, it would stand everything we know to date upon it's head.

    Umm, fusion is most certainly NOT impossible. Stand outside tomorrow around noon and look up at the sky. See that big burning thing that hurts your eyes? That's a nuclear fusion reaction.

  2. first break even?? by thesupraman · · Score: 5, Informative

    Ahh, hasn't break even been passed experimentally quite some time ago?

    http://www.jaeri.go.jp/english/fusion/fusion.htm l

    This claims break even in 1996, and 1.25 power increase in 1998 in the JT-60 tokamak..

    And this article seems to be stating they plan to hit breakeven in 2014 or further out.. hmmm.. perhaps they mean some special kind of break even, like the first ones using our method, or in the US, or something like that..

    1. Re:first break even?? by Hal-9001 · · Score: 5, Informative

      From reading the press release from 1998, it sounds like they defined the break-even condition as when the output power from the plasma exceeds the power input required to form the plasma. However, one generally would like to keep the plasma confined, and that also requires input power, so while they may have exceeded plasma break-even, they might not have exceeded overall break-even, which is a necessity for a viable power plant.

      --
      "It take 9 months to bear a child, no matter how many women you assign to the job."
  3. More info by daveschroeder · · Score: 5, Informative

    National Ignition Facility home page
    National Ignition Facility project status and photo gallery with lots of pictures
    LLNL Science on High Energy Lasers

  4. I don't think that's very much energy by HawkinsD · · Score: 5, Informative

    Let's see...

    Assuming that '500 trillion' means 500 x 10^12 watts... They said it would be for a 'few billionths' of a second: maybe 2 x 10^-9 seconds?

    Am I counting wrong, or does that come out to about a million watt-seconds, or 0.277 kilowatt-hours?

    I consume more energy than that makin' coffee.

    --
    Never attribute to malice that which can be explained by mere idiocy.
  5. Calculation a bit off by Anonymous Coward · · Score: 5, Informative

    As Mr. Potts says, Watts are a unit of power. 500 trillion Watts is the power being put into the reaction by the lasers. Energy is not the same thing as power. Power is energy divided by time.

    According to the article, the beams will be fully on "only for a few billionths of a second". For a naive estimate of the total energy being output by the lasers, we can simply multiply (500 GW) * (2 ns).

    Now, this yields a quantity with dimensions of energy: (500 GW) * (2 ns) = (1 kJ). To get a handle on this, it is the amount of energy that is output in heat and light by a 100W light bulb shining for ten seconds.

    For a scenario Slashdotters are familiar with, it's the amount of heat generated by a 1 GHz Athlon thunderbird in 12 seconds.

  6. Power != Energy by femto · · Score: 5, Informative
    >That will have to be quite a bit, since it will take 500 trillion watts to ignite the pellet in the first place.

    Power is not the same as energy. It is energy per unit time. It is rubbish to say there will have to be a large energy output because the input power is high. By way of example, 500 trillion watts for a femtosecond = 500 joules. This is not an unreasonable amount of energy, contrary to the attempt to imply otherwise by shouting '500 trillion'.

  7. Re:Whose definition of "soon" by Eccles · · Score: 5, Informative

    Actually, if you read the article 2014 is someone else's estimate, and the scientists hope for results substantially sooner.

    I know, I know, suggest a /.er actually read the article?

    --
    Ooh, a sarcasm detector. Oh, that's a real useful invention.
  8. Re:More energy than put in? by ars · · Score: 5, Informative
    This is completely NOT TRUE! Moderators: Just because he sounds like he knows what he's talking about doesn't make it true!

    You can buy pure heavy water for about $300 per Kg. Making tritium from that is simple. The AC is delusional, you don't need to make it atom-by-atom. Just put some heavy water need a reactor for a couple of days and you're all set!

    As I source I give you this link Heavy Water: A Manufacturers Guide for the Hydrogen Century.

    As for his "ideal" proton-proton reaction. First of all it's not in the slighest bit ideal. A Deuterium-Deuterium reaction is the ideal one. You can't make a proton-proton reaction anyway - you need neutrons. And guess what you do with the neutrons? You attach them to protons and make: you guessed it, deuterium!

    The only thing the sun does, which we would not do in a lab is convert protons to neutrons by adding electrons. That's the only thing that you are not going to see mass produced in a lab. The sun does not do proton-proton fusion, you can't do that. What the sun does it take protons convert half ot them to neutrons, and hook them up with protons to make deuterium. Then it does deuterium-deuterium fusion.

    --
    -Ariel