The determination of 125I activity using sum-peak method with a well-type HPGe-detector-based spectrometer

This paper describes the determination of 125I activity by using the sum-peak method with a well-type HPGe-detector-based spectrometer. The activity equation for 125I, which is free of nuclear parameters and detector efficiency, is developed. By using this method, we have determined the specific activity of an international comparison solution of 125I provided by the Electrotechnical Laboratory (ETL) of Japan. The result is in good agreement with those of ETL and BIPM, proving the validity of the new absolute method for the determination of 125I activity.