Monte Carlo simulation to determine the correction factor for gamma-ray self-attenuation

The low background gamma spectroscopy using a High-Purity Germanium (HPGe) semiconductor detector is widely used in Vietnam. When using this technique, we must pay attention to the phenomenon of gamma self-attenuation in the measured samples. Particularly, when determining the activity concentration of radionuclides that emit low-energy gamma, self-absorption can significantly reduce the detector's count rate and give a rise in the error of measured results. In this report, we determined the gamma self-attenuation correction factor using the Monte Carlo simulation method. (author)