Measurement of escape energy from absorber in calorimetric determination of 192Ir radioactivity

An improved method for the measurement of the escape energy from the absorber is proposed, which is formulated based on the air kerma and the effective mass energy-absorption coefficients in air for the escape photon spectrum. By applying the method, the escape energy from the tungsten absorber with sealed 192Ir source in it was measured. The ion chamber-type detector was used to measure the air kerma rates due to the escape photons. From the energy spectrum obtained by means of HPGe spectrometry, the effective mass energy-absorption coefficient in air for the escape photons was evaluated. The proposed method can be used for any other radioactive sources.