Dose Course Book

Previous Page

Next Page

Page Background

Beam Profiles: Penumbra measurements

using detectors of different sizes

The volume effect

6 MV,

d

(1.4 cm depth)

6 MV, 30 cm depth

max

31002 is a 125 mm

3

air ion chamber (PTW)

80/20%

31002 is a 125 mm

3

air ion chamber (PTW)

80/20%

Krauss [20]

Penumbra widening due to

overestimated beam tails

(scattered radiation outside

beam – energy dependence)