- #1
kmoh111
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Homework Statement
This problem comes from Frank Attix's book Intro to Radiological Physics and Rad Dosimetry.
From ch. 4 - problem #1:
Approximately what diameter for a sphere of water would be required to approach radiation equilibrium wihin 1% at its center, assuming it contains a uniform dilute solution of 60Cobalt (1.25 MeV gamma rays). Use u(en) and u as approximations to the effective gamma ray attenuation coefficient; this will over- and under-estimate the size respectively.
Homework Equations
u - is the attenuation coefficient for primary photons only
u(en) - is the effective attenuation coefficient for ideal broad beam attenuation
Attix gives the solutions as 312 cm and 144 cm
The Attempt at a Solution
I come close to one of the answers but I'm not sure how u and u(en) come into play here.
(4/3) pi r^3 = .01(1.25MeV).
This gives r = .144