Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Tunneling effect problem

  1. Mar 13, 2007 #1
    1. The problem statement, all variables and given/known data

    We consider a simple model of alpha decay. Imagine an alpha particle moving around inside a nucleus. When the alpha bounces against the surface of the nucleus, it meets a barrier caused by the attractive nuclear force. The dimensions of this barrier vary alot from one nucleus to another, but as representative numbers you can assume that the barriers width is 35 fm and the average barrier height U0 x E = 5MeV. Find the probability that an alpha particle hitting the nuclear surface will escape. Given that the alpha hits the nuclear surface about 5x10^21 times per sec, what is the probability that it will escape in a day?

    2. Relevant equations

    Transmission probability is given by:
    T(E) = {1+1/4[U^2/E(U-E)]sinh^2ALPHA*L}^-1
    ALPHA = sqrt(2m(U-E))/h.bar

    There are 86400s in a day: 4.32E36 alpha-hit

    3. The attempt at a solution

    I tried using E = (h.bar^2 x k^2)/2m but then it gives me a really really weird answer. Can anyone help me crack this problem?
  2. jcsd
  3. Mar 13, 2007 #2
    My E

    The E that I got using the above formula is 2.633E15!!!
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook