Ferrous sulphate dosimeter for control of ionization chamber dosimetry of electron and 60Co gamma beams.

A check of the dosimetry using ionization chambers and applying the procedures described in the Nordic dosimetry protocols (NACP 1980, 1981) was carried out using the ferrous sulphate dosimeter as reference. Measurements have been carried out in electron beams in the energy range 2.8 to 27.5 MeV and in 60Co gamma beams. Consistent results were obtained with the two systems within about one per cent. Larger differences were only observed in electron beams containing a large proportion of scattered low energy electrons and contaminating roentgen rays which were not corrected for in the ionization chamber method.