Determination of gamma-ray efficiency curves for volume samples by the combination of Monte Carlo simulations and point source calibration

In general, radioactivity measurements for volume samples are performed by the gamma -ray spectrometry method with germanium detectors. In the method, peak efficiency curves must be obtained for each kind of sample in advance . For the reason, usually, many standard volume sources have been made whic h have different shapes, densities, matrix compositions and so on. This pap er describes about a simple method for determination of gamma -ray efficien cy curves by the combination of Monte Carlo simulations and a single-point calibration using a standard point source. This method enables us to determ ine the efficiency curves for various types of samples and detectors easily and precisely.