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Spontaneous endothermic nuclear reaction?

  1. Sep 24, 2008 #1
    is such a thing possible? I am curious to know if this could/does exist.

    An alternative would be if someone gave an example of a reaction where electron capture occurs and the product ends up being stable enough to not decay into anything further.


    (btw, does cold fission exist? If so, is there an example/article/video about it?)
  2. jcsd
  3. Sep 25, 2008 #2


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    What is cold fission?

    You mean cold fusion right?
  4. Sep 25, 2008 #3
    To have a spontaneous endothermic reaction, say,

    A + e = B

    the difference between internal energies of B and A has to be greater than zero (or else the process is not endothermic), but smaller than the energy of the electron (or else the reaction won't go through).

    This is extremely improbable at room temperature, because nuclear energy levels are measured in keV and MeV, and room-temperature electron energies are fractions of eV.

    One way to think about it is to reverse the process. A forward process (endothermic electron capture) is a reverse of beta decay. If you can find an isotope that goes through a beta decay and only emits 1 keV or less in energy, you can put the process in reverse by heating the product of beta decay and eventually you'll start seeing what you want.

    Makes sense?
  5. Sep 25, 2008 #4
    To 1st poster: Fission, fusion, whichever. As long as it's cold.

    And to 2nd poster, is there an example of this?
  6. Oct 1, 2008 #5
    does anyone know an example of the stuff mentioned in first post?
  7. Oct 5, 2008 #6
    hamster, would heating the beta decay product into the reaction be spontaneous?
    Last edited: Oct 5, 2008
  8. Oct 6, 2008 #7
    Define "spontaneous".
  9. Oct 7, 2008 #8
    Dictionary.com - Happening or arising without apparent external cause; self-generated; natural and unconstrained

    btw, do you know of anything that emits only 1 keV or less when it beta decays or anywhere where I can find such information?
  10. Oct 8, 2008 #9
    There are some tables of nuclides online, the lowest I see is Rhenium 187 that beta decays into Osmium 187 and emits 2.6 keV. I can't find any references that the inverse process is in fact possible, but it should be.

    "Spontaneous" usually refers to decays, it's not commonly used for many-body interactions.
  11. Oct 14, 2008 #10
    I think spontaneous just means it will occur without any prodding from us.

    so a < 1keV beta decay doesn't exist?
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