The Use of Plane Parallel Ionization Chambers in High Energy Electron and Photon Beams

This report both complements and extends Technical Reports Series No. 277/2, Absorbed Dose Determination in Photon and Electron Beams - An International Code of Practice, IAEA Technical Reports Series No. 277/2. It describes options and how to calibrate plane parallel ionization chambers, against air kerma or absorbed dose to water standards at cobalt-60 gamma ray energies. The use of these chambers to calibrate therapy electron beams, as well as relative dose measurements for photon and electron beams, is presented. This publication also updates some of the data and concepts used in Technical Reports Series No. 277/2. It fills gaps in the latter report with respect to plane parallel chambers with a view to improve accuracy in radiotherapy when these chambers are used.