محاسبات دزیمتری سیستم فرضی P‌GNAA با استفاده از فانتوم ORNL-MIRD و کد محاسباتی مونت کارلو

Increasing growth of terrorist's activities and threats to date and illegal transit of cargo led to the discovery and detection systems which have a lot of development. In this paper, Prompt Gamma Neutron Activation Analysis (PGNAA) technique has been used to discovery and detection of materials. Besides using simulated hypothetical system, should also pay special attention to safety radiation and considerations related to the physics of health issues. If the amount of dose is relatively large, appeared deterministic effects and probable effects may occur at all radiation levels. Therefore, to determine allowable and protected region, ORNL-MIRD phantom has been used. ORNL-MIRD phantom provides analytical model of the human body. Calculation of doses in organs requests an exact description of the geometry of organs and the chemical constitution of tissues. At the available hypothetical system, the 252Cf source and NaI detector were used as neutron generator and emitted gamma receiver respectively. MCNPX2.7 code was exploited to simulate neutron - photon transport in this system. Considering details of the existing system, protected region within a radius of 70 cm and the allowable region for radiographers as 130 cm radius were obtained. Also the designed system is capable of detecting HMX explosive with weights of 158 gr and 501 gr at 10 and 1 minute respectively.