Study on detection geometry and detector shielding for portable PGNAA system using PHITS

International Nuclear Science, Technology and Engineering Conference 2017

原子能学

Ithnin, H.^1,4 ; Dahing, L.N.S.^1 ; Lip, N.M.^2 ; Abd Rashid, I.Q.^3 ; Mohamad, E.J.^4

Industrial Technology Division, Malaysia Nuclear Agency, Malaysia^1

Faculty of Computer and Mathematical Science, Universiti Teknologi Mara, Malaysia^2

Department of Nuclear Science, Universiti Kebangsaan Malaysia, Malaysia^3

Faculty of Electrical and Electronic Engineering, Universiti Tun Hussein Onn, Malaysia^4

关键词: Absolute efficiencies;    Detection geometry;    Efficiency studies;    Gamma-ray detection;    Prompt gamma-ray neutron activation analysis;    Prompt gammas;    Shielding materials;    System-setup;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/298/1/012053/pdf
DOI  :  10.1088/1757-899X/298/1/012053

来源: IOP

【 摘 要 】

Prompt gamma-ray neutron activation analysis (PGNAA) measurements require efficient detectors for gamma-ray detection. Apart from experimental studies, the Monte Carlo (MC) method has become one of the most popular tools in detector studies. The absolute efficiency for a 2 × 2 inch cylindrical Sodium Iodide (NaI) detector has been modelled using the PHITS software and compared with previous studies in literature. In the present work, PHITS code is used for optimization of portable PGNAA system using the validated NaI detector. The detection geometry is optimized by moving the detector along the sample to find the highest intensity of the prompt gamma generated from the sample. Shielding material for the validated NaI detector is also studied to find the best option for the PGNAA system setup. The result shows the optimum distance for detector is on the surface of the sample and around 15 cm from the source. The results specify that this process can be followed to determine the best setup for PGNAA system for a different sample size and detector type. It can be concluded that data from PHITS code is a strong tool not only for efficiency studies but also for optimization of PGNAA system.