I need the answers for the two questions Thank you 1 Gamma

I need the answers for the two questions. Thank you !!

1.- Gamma Attenuation. Ga concrete plates of thicknesses Ls and Lc respectively as emit gamma rays with energies of 400 Kev and 200 Kev, respectively. The hitting the steel plate are l 20,000 photons/cm\'s, and lon 40,000 mma radiation from radioactive material is shielded using steel and shown below. Two radloactive sources, A and B intensities of gamma rays 20,000 photons/cm\'s, and I\' 40,000 photons/crm, are Io Radioactive Sources 1.1 Does the order of the plates (steel plate first or concrete plate first) make a difference in the effectiveness of the shielding? Explain why 1.2 List all types of interaction that gamma rays from sources A and B are likely to have with nuclei in these plates. Explain clearly each type of interaction. If a type of interaction is unlikely to happen, explain why.

Solution

Attenuation of a gamma

Of the three types of radiations, gamma rays are the most penetrative and therefore the most difficult to avoid. In theory, they can never be completely stopped, but only attenuated. In practice, however, severe attenuation is as good as a cut-off. This objective is achieved by most of the protective screens in radioprotection..

The attenuation with a screen comes in addition to the solid angle effect, which is purely geometrical and states that the number of photons hitting a target in vacuum drops as the square of the distance to the source.