An isotropic point source of therma neutrons is placed at the center
of a uniform spherical medium of radius R, with a scattering cross
section S and absorbtion cross section A , the sphere is in vacuum. If
S is zero, what is the probability that the source neutron will escape
from the sphere? and If S is not zero? why the leakage probability is
different in both cases? calculate the leakage probability for
graphite?

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Request for Question Clarification by mathtalk-ga on 17 Oct 2003 07:56 PDT

Hi, justin1-ga:

Without more detailed information it would be impossible to compute
the specific probability that the neutron will escape from the sphere,
although with a bit of additional notation a formula can be given.

It can be cogently argued what kind of effect taking S nonzero will
have on the probability of escape, although again not enough
information is provided to make a numerical calculation.

I'm wondering what kind an answer, esp. to the last part "calculate
the leakage probability for graphite", you require for the list price
offered.

Thanks in advance,
mathtalk-ga

I hate to say this, but it sounds suspiciously like a calculation
relevant to an implosion bomb. Not to say that you are desiging a
bomb, but only to say that it might not be prudent to publish such an
answer, even if it's openly available, on Google answers. Just my
opinion.

-Mark Martin

Posting an answer to this question will not make it any easier for
anyone to build a nuclear bomb.  GMAB.