Does the photon beam quality factor depend on the type of ionization chamber?
The photon beam quality factor Q of 6- and 15-MV photon beams has been measured using different types of thimble ionization chambers with various wall, electrode and insulator materials. Some types of chambers seem to overestimate the corresponding Q-value by 0.4% (6 MV) and 0.7% (15 MV), respectively. The effect on the stopping power ratio water to air and on the pertubation correction will be discussed.
Christ
G
G
Abteilung Medizinische Physik, Radiologische Universitätsklinik Tübingen, Germany.
Major
J
J
Nüsslin
F
F
D017785:Photons; D011874:Radiometry / Q000295:instrumentation*