SK1 (right) and the new SK2 (left). Note the radiation damage (yellow color) on the older phantom.
SK2 mounted to the Gantry.
The SK2 ("Strahlerkopf-Phantom 2") is an alternative to SK1, which has been used as a weekly dose measurement phantom for over 8 years.
SK2 uses Farmer chambers, the measurement depth of 1cm PMMA is the same for all energies (4-20MeV electrons, 6&15MV photons). Despite the fact that photon dose is measured in the buildup region of the deph dose curve, the chamber gives stable readings with similar standard deviation for all eight energies. The advantages are that one needs not enter the treatment room when changing energies. Plus it is lightweight and easier to grab (aluminum tubes with round cross section).
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SK1 (right) and the new SK2 (left). Note the radiation damage (yellow color) on the older phantom. |
SK2 mounted to the Gantry. |
Some port images of SK2:
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Photo10x10 field and Farmer chamber (aS500 image) |
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Beams-Eye-View of SK2 showing the four aluminum tubes in the corners, the central bock of PMMA and the Farmer chamber (aS500 image) |