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Laser fusion and science fiction

  1. Jun 10, 2009 #1
    I'm a science fiction writer, currently I write a novel related to laser fusion. As I know in chemistry, catalysis is the process in which the rate of a chemical reaction is either increased or decreased by means of a chemical substance known as a catalyst.

    Are there catalysts in the nuclear fusion? ( for example gold nanoparticles )
    In the laser fusion, D-T fuse at 100 million degrees C.

    Could D-T with gold nanoparticles fuse at less than 100 million degrees C ?

    Thanks
     
  2. jcsd
  3. Jun 10, 2009 #2
    Gold-deuterium fusion would be endothermic, and besides very difficult to achieve due to the high coulomb barrier of the gold nucleus (more protons).

    Before they redid their page, ITER had a nice graph of fusion fuels' reactivity versus temperature, and it had "catalyzed D-D" as one of the fuels, but I do not know how one can "catalyze" ANY fusion (well, they call one method "muon catalyzed fusion" but that's currently unobtainium).

    If talking about laser fusion, there is a method to reduce the laser energy use. HiPER uses fast ignition, which means that the fuel pellet is first compressed with lasers, normally, but it contains a small gold cone which allows another laser to fire to the center of the pellet, triggering the fusion reaction with less effort than just compression. That involves gold and "catalyzes" the fusion, so that might be something you're looking for.

    Edit: so, if you want to maintain scientific accuracy in your writing, don't call the fast ignition method catalysis, because it is not catalysis by definition.
     
  4. Jun 10, 2009 #3
    Nyme , first i thank you very much for your help.
    about the small gold cone used in the fast ignition i want to know what will happen to that cold ?
     
  5. Jun 10, 2009 #4
    No problem.

    I'm assuming you meant "what will happen to that cone" instead of what will happen when it's cold...

    Well, didn't read this from anywhere, but it will most certainly be vaporized, of course depending on the amount of fusion fuel burned. But at any commercial-scale reactor with pellet fusion energies reaching multiple gigajoules, it will be vaporized.

    And no, I don't know how they recycle that gold.

    By the way, if you need more information on the aspect, have a look at their website at
    http://www.hiper-laser.org/index.asp [Broken]

    Edit: a clarification
     
    Last edited by a moderator: May 4, 2017
  6. Jun 10, 2009 #5
    I already read the information in that website , but they didn't write anything about 'what will happen to the gold cone..
    thanks
     
  7. Jun 20, 2009 #6
    Hi

    You should check out Friedwardt Winterberg's work on pulsed fusion. He thinks the current laser fusion approach is unworkable because the flash-back destroys the optics when the lasers are powerful enough to trigger fusion. His current fusion triggering designs use proton beams or one-shot explosion-driven argon lasers. The proton-beam system would be for a fixed power-plant, but the one-shot lasers are for a pulse-driven rocket.
     
  8. Jun 20, 2009 #7

    Astronuc

    User Avatar

    Staff: Mentor

    In brief, no, and Nyme explained why.

    In laser fusion, the objective is to heat the surface of a DT capsule, which is at cryogenic (solid hydrogen) temperatures. The laser light light heats an external layer which ablates. The ablation then cause the fuel capsule/target to impode or compress very rapidly. The rapid compression heats the fuel and increases the density to the conditions necessary for fusion.

    Here is some information on the target capsules used in a proposed inertial confinement scheme.

    https://lasers.llnl.gov/programs/nic/target_fabrication.php [Broken]
    https://lasers.llnl.gov/programs/nic/target_physics.php [Broken]
    https://lasers.llnl.gov/programs/nic/icf/how_icf_works.php [Broken]
     
    Last edited by a moderator: May 4, 2017
  9. Jun 25, 2009 #8

    mheslep

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    Gold Member

    (Muon catalyzed fusion is very obtainium, has been for decades, just not practium)
     
  10. Jun 25, 2009 #9
    The chief problem is getting the muons to remain in combination for long enough to fuse, but not too long, else they decay before they can catalyse more reactions. I think the current record is about 100 fusions catalysed per muon which falls short of breakeven. A more efficient muon-generator might mean that's enough, but most researchers think they've hit the limits of the practical. But not everyone agrees, so maybe one day...
     
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