Page 308 - Radiation Safety
P. 308
PROTECTION AGAINST EXTERNAL HAZARDS
(SHIELDING)
Solution
No. of HVL, 2 n = Doserate before shielding / Doserate after
shielding
= 40/2.5
= 16
n ln2 = ln16
n = ln16 / ln2
= 4 (HVL)
Therefore, thickness required of HVL = 4 x 6.5
= 26mm of lead.
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