4. You need to determine how far into the brain x-rays from Fe-55 radioactive source will...

 

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4. You need to determine how far into the brain x-rays from Fe-55 radioactive source will penetrate in order to measure the amount of Al in brain plaque. Determine the expected intensity of the x-rays at the brain if the initial x-ray intensity was I, = 10,000 counts per second. Model the head as being made up of 1-mm of skin (p = 1.1 g/cm) (nylon, C12H22O3N) and 10-mm of bone (CaPO) (p = 1.3 g/cm). The mass attenuation coefficients for this x-ray energy are listed below in the table. (20 pts.) II, ex. Determine the intensity thru each layer using this equation. Element skin Atomic H, cm/g Wt% Mass Weight attenuations 228.0 14.22 HCON 1.0 0.4 9.65 0.04 12.0 11.1 63.16 7.01 16.0 28.6 21.05 6.02 14.0 18.7 6.14 1.15 total 6 pts 14.22 bone 254.2 Ca 40.1 398.0 31.55 125.57 P 31.0 186.0 24.39 45.37 O 16.0 28.6 44.06 12.60 total 6 pts 183.54 x-ray absorption in skin 2093 cps after skin 4 pts x-absorption in skull 0.00 cps after skull 4 pts 4. You need to determine how far into the brain x-rays from Fe-55 radioactive source will penetrate in order to measure the amount of Al in brain plaque. Determine the expected intensity of the x-rays at the brain if the initial x-ray intensity was I, = 10,000 counts per second. Model the head as being made up of 1-mm of skin (p = 1.1 g/cm) (nylon, C12H22O3N) and 10-mm of bone (CaPO) (p = 1.3 g/cm). The mass attenuation coefficients for this x-ray energy are listed below in the table. (20 pts.) II, ex. Determine the intensity thru each layer using this equation. Element skin Atomic H, cm/g Wt% Mass Weight attenuations 228.0 14.22 HCON 1.0 0.4 9.65 0.04 12.0 11.1 63.16 7.01 16.0 28.6 21.05 6.02 14.0 18.7 6.14 1.15 total 6 pts 14.22 bone 254.2 Ca 40.1 398.0 31.55 125.57 P 31.0 186.0 24.39 45.37 O 16.0 28.6 44.06 12.60 total 6 pts 183.54 x-ray absorption in skin 2093 cps after skin 4 pts x-absorption in skull 0.00 cps after skull 4 pts