A calculation of relative efficiencies of a GEM-based neutron detector using different solid neutron converters

International Nuclear Science and Technology Conference 2016

Rittirong, A.^1 ; Sripreeprem, S.^1 ; Saenboonruang, K.^1

Department of Applied Radiation and Isotopes, Faculty of Science, Kasetsart University, Chatuchak, Bangkok

10900, Thailand^1

关键词: Absorption cross sections;    Detection capability;    Detection efficiency;    Efficiency calculations;    Gas electron multipliers;    Nuclear interaction;    Thermal neutron detectors;    Typical application;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/860/1/012018/pdf
DOI  :  10.1088/1742-6596/860/1/012018

来源: IOP

【 摘 要 】

A Gas Electron Multiplier (GEM) detector is one of the most promising particle detectors nowadays due to its excellences in high rates of detection capability, good spatial resolution, and flexibility in designs. In addition to typical applications of ionizing particle detection, the GEM detector could also be modified to detect thermal neutrons by coating suitable solid neutron converters to its GEM drift cathode. Although, wide selections of materials are available to be used as neutron converters, most suitable ones must have high neutron-absorption-cross-section properties as more chances of nuclear interactions between thermal neutrons and their nuclei are desirable. Another factor that plays important roles to detection efficiencies in addition to types of materials is thicknesses of coating layers. Although thicker layers mean higher numbers of nuclei available for interactions with neutrons, ionizing particles produced after the interactions have less chances of successfully penetrate thick layers to ionize gas molecules for detection. Consequently, an optimum thickness for each material is crucial for GEM-based thermal neutron detector and must be carefully determined. This article aims to illustrate in-depth calculations to find these optimum thicknesses and their corresponding relative efficiencies for different solid neutron converters including6Li,natLi,10B,natB,113Cd,natCd,149Sm, andnatSm, using a simulation and actual data of GEM's properties. Basic information of GEM detector and neutron detection, simulations, efficiency calculations, results, and discussion will be thoroughly reported in this article.