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Lawson's Criterion

  1. Apr 20, 2005 #1
    What is the basis for Lawson's criterion? How is it derived?

    Does it apply to all plasmas or only to magnetically confined plasmas?
  2. jcsd
  3. Apr 20, 2005 #2


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    Lawson's criterion is a rough estimate for the conditions required for
    fusion - any basic fusion text will give you the details.

    It applies for ALL fusion schemes - regardless of the confinement
    mechanism. It's interesting to see how the various fusion schemes
    fulfill the Lawson criterion.

    Take magnetic confinement. In magnetic confinement, the plasma
    densities are fairly low - anyone else would call them a pretty good
    vacuum. But the confinement times are on the order of a second or
    a few seconds.

    At the other end of the spectrum is inertial confinement fusion - also
    called "laser fusion". Here there is no attempt made to try to confine
    the plasma - only the plasma's own inertia limits its expansion.
    Confinement times here are extremely small - on the order of
    nanoseconds. However, the densities are extremely high - on the order
    of 10,000 grams per cubic centimeter. So the product can also fulfill
    the Lawson criterion.

    So we have two extremes - low density, but high confinement time
    [ magnetic fusion ] or high density, low confinement time [ inertial
    confinement fusion ]

    Dr. Gregory Greenman
  4. May 12, 2005 #3
  5. May 13, 2005 #4


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