Physics Bucharest 2017
Example for primary beam
Waiting room adjacent to a linac bunker
Equipment type = linac, FAD = 1m, 6MV W = 40000Gy/year D = 2.5Gy U = 0.25 (lateral approach) d = 6m T = 0.25 (waiting room) E = 0.001Gy/year (limit value in the area to be shielded d 0 as the distance from source to reference point (e.g. isocentre)
E 0
= WUT (d ref
/d) 2 = 69.444
n= -log(E/E 0
)= 5
Need to know the TVL (tenth value layer or thickness required to attenuate the beam by a factor of 10) of concrete in a 6MV beam -> TVL ≈ 30cm
Required barrier thickness: t pri
= nTVL= ??? m
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