A beam of photons passes through a muscle of thickness L. Assume that muscle has a mass density ρ and energy absorption coefficient μen. The energy fluence of the beam is ψ(x), at depth x.
a) What is the dose where the beam enters the muscle (the skin dose)?
b) Find the total energy absorbed per unit area in muscle of thickness L. Also find the average dose for the muscle. Your answers should be in terms of ψ(x), ρ , L, and μen .
c) Find the limiting values of the average dose as L ==> 0 and as L==>∞.