Design of detector to monitor the Bragg peak location of carbon ions by means of prompt γ-ray measurements with Geant4  

作　　者：Yan Fan Guang-Ming Huang Xiang-Ming Sun Zhen Wang Shu-Guang Zou Jun Liu Dong Wang Hui-Li Kang Ping Yang Hua Pei Da-Ming Sun Zi-Li Li 

机构地区：[1]PLAC, Key Laboratory of Quark & Lepton Physics (MOE),Department of Physics Science and Technology, Central China Normal University, Wuhan 430079, Hubei, China

出　　处：《Nuclear Science and Techniques》2018年第4期83-91,共9页核技术（英文）

基　　金：supported by the National Natural Science Foundation of China(Nos.11375073 and U1232206)

摘　　要：Real-time monitoring of the Bragg peak location of carbon ions is urgently required for the quality control of hadron therapy. In this study, we design an annular detector to monitor the Bragg peak location of carbon ions with Geant4 simulation. This 360° surrounding structure has a high detection efficiency for the small-dose situation. The detector consists of a multilayered collimator system and an Na I scintillator for prompt gamma counting. The multilayered collimator includes a lead layer to prevent unwanted gammas and the paraffin and boron carbide layers to moderate and capture fast neutrons. An inclination of the detector further diminishes the background signal caused by neutrons. The detector, with optimized parameters, is applicable to carbon ions of different energies. In addition, the scintillator is replaced by an improved EJ301 organic liquid scintillator to discriminate gammas and neutrons. Inserting thin Fe slices into the liquid scintillator improves the energy deposition efficiency. The Bragg peak location of 200 Me V/u carbon ions can be monitored by prompt gamma detection with the improved liquid scintillator.Real-time monitoring of the Bragg peak location of carbon ions is urgently required for the quality control of hadron therapy. In this study, we design an annular detector to monitor the Bragg peak location of carbon ions with Geant4 simulation. This 360° surrounding structure has a high detection efficiency for the small-dose situation. The detector consists of a multilayered collimator system and an Na I scintillator for prompt gamma counting. The multilayered collimator includes a lead layer to prevent unwanted gammas and the paraffin and boron carbide layers to moderate and capture fast neutrons. An inclination of the detector further diminishes the background signal caused by neutrons. The detector, with optimized parameters, is applicable to carbon ions of different energies. In addition, the scintillator is replaced by an improved EJ301 organic liquid scintillator to discriminate gammas and neutrons. Inserting thin Fe slices into the liquid scintillator improves the energy deposition efficiency. The Bragg peak location of 200 Me V/u carbon ions can be monitored by prompt gamma detection with the improved liquid scintillator.

关 键 词：Braggpeak Carbonion Promptc-ray GEANT4 

分 类 号：TL[核科学技术]