Evaluating analytical ionization quenching correction models for 3D liquid organic scintillator detector

9th International Conference on 3D Radiation Dosimetry

Alsanea, F.^1 ; Beddar, S.^1

Department of Radiation Physics, University of Texas, MD Anderson Cancer, Houston

TX, United States^1

关键词: Ionization quenching;    Liquid organic scintillator;    Organic scintillator;    Quenching parameters;    Scintillation light;    Scintillation measurements;    Secondary electrons;    Semi-empirical formulas;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/847/1/012022/pdf
DOI  :  10.1088/1742-6596/847/1/012022

来源: IOP

【 摘 要 】

Proton therapy offers dosimetric advantage over conventional photon therapy due to the finite range of the proton beam, which improves dose conformity. However, one of the main challenges of proton beam therapy is verification of the complex treatment plans delivered to a patient. Thus, 3D measurements are needed to verify the complex dose distribution. A 3D organic scintillator detector is capable of such measurements. However, organic scintillators exhibit a non-linear relation to the ionization density called ionization quenching. The ionization quenching phenomenon in organic scintillators must be accounted for to obtain accurate dose measurements. We investigated the energy deposition by secondary electrons (EDSE) model to explain ionization quenching in 3D liquid organic scintillator when exposed to proton beams. The EDSE model was applied to volumetric scintillation measurement of proton pencil beam with energies of 85.6, 100.9, 144.9 and 161.9 MeV. The quenching parameter in EDSE model ρqwas determined by plotting the total light output vs the initial energy of the ion. The results were compared to the Birks semi-empirical formula of scintillation light emission.