J Med Phys Close
 

Figure 1: An amateur digital camera image of the surface water displacement at the edge of water phantom at two different timing: (a) before moving the arm and (b) during the arm movement. The amplitude of the waves might be larger than what is seen. Amplitude of 1 mm is observed. This causes a displacement of about 2 mm over the detector. (c) A typical PDD curve for 4 MeV electron beam, 10 × 10 open field with no applicator. The PDD drops ~65% in 5 mm

Figure 1: An amateur digital camera image of the surface water displacement at the edge of water phantom at two different timing: (a) before moving the arm and (b) during the arm movement. The amplitude of the waves might be larger than what is seen. Amplitude of 1 mm is observed. This causes a displacement of about 2 mm over the detector. (c) A typical PDD curve for 4 MeV electron beam, 10 × 10 open field with no applicator. The PDD drops ~65% in 5 mm