Standardisation of ~(124)SB and ~(152)EU using software coincidence counting system

摘要

Activities of the radionuclides ~(124)Sb and ~(152)Eu were determined by the efficiency extrapolation method applied to 4pi(PC)-gamma coincidence counting. The ~(124)Sb sources were prepared from a solution with the chemical form of 50 (mu)g g~(-1) SbCl_(3) in 2 M HCl. To inhibit the volatility of antimony chlorides, the sources were slowly dried in a H_(2)S atmosphere with relative humidity of 76percent for about 48 h. This procedure increased the beta detection efficiency up to 0.98, which simplified the standardisation. In the ~(152)Eu standardisation, the optimal gamma-ray energy window setting to achieve a linear dependency and the correct slope of the extrapolation curve were derived by means of software coincidence counting system using offline evaluation of data with different coincidence parameter settings. The results obtained by the software coincidence counting system were compared with those obtained by the conventional coincidence method.