ESTRO course Dose Modelling and Verification 2017

Electron contamination

Contaminated beam

25x25 cm 2

”Clean” beam

Contaminated - ”Clean”

10x10 cm 2

7x7 cm 2

5x5 cm 2

Maximum penetration depth appr. MV/3 [cm 2 /g], i.e. deeper than d max .... Field size most important factor for magnitude, no impact on penetration depth.

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Sjögren & Karlsson, Med. Phys. 23 1996 p 1873-1881