GEANT4 simulation study of over-response phenomenon of fiber x-ray sensor  

作　　者：Bin Zhang Tian-Ci Xie Zhuang Qin Hao-Peng Li Song Li Wen-Hui Zhao Zi-Yin Chen Jun Xu Elfed Lewis Wei-Min Sun 张彬;谢天赐;秦壮;李昊鹏;李松;赵文辉;陈子印;徐军;Elfed Lewis;孙伟民(Key Laboratory of In-fiber Integrated Optics,Ministry of Education,Harbin Engineering University,Harbin 150001,China;Electronic Engineering College,Ministry of Education,Heilongjiang University,Harbin 150001,China;Comprehensive Cancer Center,First Affiliated Hospital of Harbin Medical University,Harbin 150001,China;Comprehensive Cancer Center,Second Affiliated Hospital of Harbin Medical University,Harbin 150001,China;Optical Fiber Sensors Research Centre,University of Limerick,Castletroy,Limerick,Ireland)

机构地区：[1]Key Laboratory of In-fiber Integrated Optics,Ministry of Education,Harbin Engineering University,Harbin 150001,China [2]Electronic Engineering College,Ministry of Education,Heilongjiang University,Harbin 150001,China [3]Comprehensive Cancer Center,First Affiliated Hospital of Harbin Medical University,Harbin 150001,China [4]Comprehensive Cancer Center,Second Affiliated Hospital of Harbin Medical University,Harbin 150001,China [5]Optical Fiber Sensors Research Centre,University of Limerick,Castletroy,Limerick,Ireland

出　　处：《Chinese Physics B》2021年第4期633-639,共7页中国物理B（英文版）

基　　金：Project supported by the Natural Science Foundation of Heilongjiang Province;China(Grant No.ZD2019H003);the Joint Research Fund in Astronomy under Cooperative Agreement Between the National Natural Science Foundation of China and Chinese Academy of Sciences(Grant Nos.U1631239 and U1931206);the 111 Project;China(Grant No.B13015);the Fundamental Research Funds for the Central Universities to the Harbin Engineering University;China。

摘　　要：The purpose of this article is to explore the cause of the over-response phenomenon of fiber x-ray sensor.The sensor is based on a length of PMMA fiber,whose end is filled with the scintillation material Gd_(2)O_(2)S:Tb.The Monte Carlo simulation software GEANT4 uses the phase space file provided by the International Atomic Energy Agency(IAEA),by irradiating the fiber x-ray sensor in the water phantom,counting the fluorescence signal of the optical fiber x-ray sensor after propagation through the fiber.In addition,the number of Cerenkov photons propagating through the fiber is also counted.Comparing this article with previous research,we believe that one of the reasons for the over-response of the fiber x-ray sensor is the non-linear response of the deposition energy of the scintillator to the fluorescence.By establishing a region of interest and counting the x-rays in this region,the simulation results show that the counted number of x-rays that may affect the fiber x-ray sensor is the biggest in the area of interest at a water depth of 5 cm.This result is close to the maximum dose point of the experimental and simulated percentage depth dose(PDD) curve of fiber x-ray sensor.Therefore,the second reason of the over-response phenomenon is believed to be fact that the inorganic materials such as Gd_(2)O_(2)S:Tb have larger effective atomic numbers,so the fiber x-ray sensors will cause more collisions with x-ray in a low energy region of 0.1 MeV-1.5 MeV.

关 键 词：fiber x-ray sensors over-response percentage depth dose(PDD) Monte Carlo(MC)simulation 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置]