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Plasma Physics

  1. Jan 10, 2016 #1
    Hello all,

    This might sound very optimistic for a project but I want to design a thermonuclear fusion reactor. Does anyone know how I can calculate the required plasma current I need in order to start a thermonuclear fusion process? I am using a mixture of Deuterium-Tritium gas.

  2. jcsd
  3. Jan 10, 2016 #2


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  4. Jan 10, 2016 #3

    Vanadium 50

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    Frankly, I don't believe you have any tritium gas. If you do, you need to contact the authorities immediately about proper disposal.

    Next, "optimistic" is not the word for it. If you said instead "I want to design a jet aircraft. Does anyone know how I can calculate how much fuel I need?" would you expect people to think you had a chance? This is even harder.
  5. Jan 10, 2016 #4
    You are right, i do not have tritium gas. This is a theoretical approach (meaning calculations) not so much practical.
  6. Jan 10, 2016 #5


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    What is your technical background? What textbooks on Plasma Physics and Fusion have you been reading so far? Have you studied Chen?

    What do you know about the various fusion reactor designs? Have you read about MFTFB? :smile: Or more modern reactor designs?
  7. Jan 11, 2016 #6
    @berkeman I have basic nuclear physics knowledge, and for the past year I've read a lot of information regarding aspects of nuclear fusion (Coulomb's barrier,quantum tunneling, Lawson's criterion-triple product etc.). I am basically interested in a TOKAMAK reactor :) I've calculated many variables regarding the plasma and its parameters plus the confinement (toroidal field) I just can't find how to calculate the plasma current.
  8. Jan 11, 2016 #7
    In reactor design studies the plasma current is typically set by a number of stability boundaries. Increasing the current increases the maximum stable pressure via the Greenwald limit. It also increases the maximum stable pressure via the Troyon limit. A simple place to start is to pick the safety factor on axis and at the edge. At the very least you want q on axis above 1 to avoid sawteeth, and q at the edge to be above 5 or so.
  9. Jan 11, 2016 #8
    Great, thank you very much!
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