How Thick Should a Concrete Wall Be to Safely Shield X-Rays in a Radiology Room?

[Millano]

Homework Statement

Calculate minimum thickness of concrete wall of radiation room (2X2X2) such that radiographer doesn't exceed dose limit. Use info below.

X ray reading surface of patient (50 cm from source) = exposure= 4.29 X 10$$^{}-4$$

effective energy of x ray beam = 40 kev

40% of x rays are transmitted

does limit =7.5 mGy per anum

linear attenuation coeficent = 1.16 cm

scattered radiation increases does by 5%

wair/e = 33.97
$$\mu$$/$$\rho$$=6.83x 10$$^{}-5$$

50 x rays taken per day

Homework Equations

intensity =1/d^2

I (X) = I0e µx

exposure X = dq/dm = $$\psi$$.($$\mu$$/$$\rho$$).e/wair

The Attempt at a Solution

well, You have to find the intensity(no of photons)/radiation of the x ray beams after passing through the patient. Using this you can calculate the thickness needed using the linear attenutation coefficient.

What I don't get is how the expousre and effective energy relate to the intensity of the beam after passing through the patient and how this changes as the distance increases

 

[Millano]

no one ?