Abstract

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Title:: Development of a low-toxicity water-equivalent liquid scintillator based on CdSe/ZnS quantum dots

Author(s):: CHU Xuegang1; WANG Junhui2; ZHANG Baoguo3; XING Xiaofen1; 1. Department of Radiotherapy, Cancer Hospital Affiliated to Shanxi Medical University/Shanxi Hospital Affiliated to Cancer Hospital, Chinese Academy of Medical Sciences/Shanxi Cancer Hospital, Taiyuan 030013, China 2. Department of Radiotherapy, Nantong Tumor Hospital, Nantong 226361, China 3. State Key Laboratory of Radiation Medicine and Radiation Protection/School of Radiation Medicine and Protection, Soochow University, Suzhou 215123, China

Keywords:: Keywords: liquid scintillator quantum dot water-equivalent Geant4

Abstract:: Abstract: Objective To develop a novel low-toxicity water-equivalent liquid scintillator with PPO as the primary luminescent substance, oil-soluble quantum dots (QD) as the secondary luminescent substance, and dodecylbenzene as the matrix. Methods The emission spectrum of PPO, as well as the absorption and emission spectra of QD were detected, and the radioluminescence tests were carried out on the scintillation liquids with different concentrations of QD as the secondary luminescent substance. After applying an empirical formula to deduce the approximate doping proportion of QD required for the tissue-equivalent liquid scintillator, the Monte Carlo simulation software Geant4 was used to accurately simulate the precise QD doping ratio, and finally, tests were conducted to evaluate the water equivalence and various dosimetric properties. Results The peak emission wavelength of PPO was 366 nm. For QD, the peak excitation wavelength was 340 nm, and the peak emission wavelength was 519 nm. Notably, the water equivalence was optimal when the QD doping concentration was 0.34 wt%. Conclusion QD can serve as the secondary luminescent substance for liquid scintillator, and the doping content of QD required to achieve water equivalent can be determined through Monte Carlo simulation.