[Quantitative determination of cutoff perturbation factor pdelta in the DIN 6800-2 (2008) by means of Monte Carlo simulations].
The new German DIN 6800-2 (2008) dosimetry protocol introduces a perturbation factor pdelta which accounts for the ionization chamber specific cutoff energy delta in the calculation of the Spencer-Attix stopping-power ratios. Quantitative values are not included in the protocol. In this study the perturbation factor was calculated for different types of ionization chambers using Monte Carlo simulations. For the choice of the cutoff energy the mean chord length of electrons in air filled cavities was calculated in a water phantom and for different beam qualities. The influence of different cutoff energies is not exceeding 0.1% for conventional ionization chambers.
Wulff
Jörg
J
Institut für Medizinische Physik und Strahlenschutz, Fachhochschule Giessen-Friedberg, Wiesenstrasse 14, D-35390 Giessen. joerg.wulff@tg.fh-giessen.de
Jany
David
D
Zink
Klemens
K
D000465:Algorithms; D004583:Electrons; D009010:Monte Carlo Method; D019047:Phantoms, Imaging; D017785:Photons; D011874:Radiometry / Q000379:methods*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D012542:Scattering, Radiation; D014867:Water
D014867:Water