Question

A beam of 0.4 MeV y-rays with an intensity 108y-rays/cm-s is incident on thin foil of target material having thickness 0.2 cm. 95 % of photons pass through the foil without making any interactions. Total energy deposited in the foil is 1.5x10 MeV/cma-s. Determine attenuation and linear absorption coefficients of target material.

Answer 1

Given Thickness of the foil, x= 0.2cm Incident gamma pays intensity, Jo = 108y-rays/cma-s Attenuation of a gamma beam is defined as the fraction of days which come through an absorber without interacting. since, 95% of photon pan through the foil with making any interaction. Intensity of radiation leaves the foil, I = 954. Io = 0.95 10 Decrease in intensity of badiation is - SI = Io I Fractional change in intensity Attenuation = 41 - -1-1 - 1-6.9513 = 1-0.95 -0.05) = 5% / attenuation

-Un Relation between I and Io using Lambert's low I(n) = To en where, a is the thickness of foil and M is the lineas absorption Coefficient. Reoranging the above equation Ma-Ten (7) se zemen ( 655) [0. 256 cm 1 |