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Alpha Particle decay

  1. May 14, 2010 #1

    I want to know why a small change in energy released, Q, in alpha particle decay leads to a large change in the lifetime. Also could anyone provide me with a link that shows a diagram of the energy spectrum of alpha particles.

  2. jcsd
  3. May 14, 2010 #2


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    Please define 'small' with respect to energy, Q.

    One can find details on specific radionuclides at - http://www.nndc.bnl.gov/chart/ (click on a particular area and choose a nuclide, then select Zoom 1 for a closeup). One can use various links to various other pages (In Zoom 1 mode - look for A list of levels, a level scheme and decay radiation information are available near the bottom of the page).

    For example -

    http://www.nndc.bnl.gov/chart/getdecayscheme.jsp?nucleus=238U&dsid=242pu a decay&unc=nds

    The general website = http://www.nndc.bnl.gov/
  4. May 18, 2010 #3
    I take it you're referring to the exponential dependence of the mean lifetime (or half-life) on the energy Q for an alpha-emitting radionuclide, as observed in the Geiger-Nuttal law?

    You can derive this if you're familiar with basic quantum mechanics, and you treat the alpha particle escaping the nucleus as a basic example of a quantum mechanical tunnelling/scattering from a bound state, as Gamow originally showed. It's often shown as an example in many undergrad quantum mechanics books.
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