مهدی سلطانی

Abstract: Gamma ray spectrometry is a practical and useful method for measuring activity. This method is safe and, in most cases, no need for sample preparation. High resolution of gamma ray detectors spectra has been introduced in various fields of industry and research, and quantitative and qualitative analyzes of radioactive materials can be made. Each gamma spectroscopy detector requires two calibrations, calibration of energy and efficiency. Energy calibration is performed once per device and does not depend on the type of sample and source. Samples can be analyzed qualitatively when calibrating energy, but the efficiency calibration required for quantitative analysis of samples is unique to each sample or source. If any chemical or physical variation in the sample, such as density, altitude, geometry, etc., occurs, this calibration must be changed and calibrated for proper efficiency. A general technique for all quantitative analyzes is that in order to carry out quantitative analysis of gamma spectra, standard samples are required for empirical and precise state calibration of the efficiency. However, this can be difficult if there are different scenarios. Standard samples are either generally or expensive or even unavailable due to the combination of some samples. Also, many standard specs need to be extended due to the short half-life of many radio nuclides. Also, the other difficulty in drawing up the calibration charts of efficiency using standard samples is that for the consideration of self-absorption, the density and composition of the standard sample must be known, especially in the case of bulk samples. Therefore, the composition and density of the Analysis sample should be known, which is not always possible. For solving this problem, there are many empirical computing codes today. ANGLE code is one of the most accurate and reliable software for calculating efficiency. This software is very accurate, fast and reliable. Also, the input information is