An Ionization Chamber for Kilocurie Source Calibrations

Abstract

A graphite cavity ionization chamber suitable for measuring the exposure dose rate (r/hr) in kilocurie Co60 [gamma]-ray sources is described, and the associated techniques involved is discussed in some detail. The chamber has excellent ion saturation properties and can be used to determine the exposure dose rate absolutely to within [plus or minus] 2% at dose rates up to 1 x 107'' r/hr. The use of chambers with walls of different atomic number to determine the influence of low-energy scattered radiation on the absorbed dose (rads) in high-z materials is also described.