Prepare Of Tissue Equivalent Radioluminescent Scintillator Material

With the development of radiation therapy technology,a new challenge has come up with the dose verification of radiotherapy.The dose distribution in human body can not be directly measured when the dose is verified,and tissue equivalent body phantom is usually used as substitutionto measure the body dose distribution,which requires the phantom and the measurement system possessing good tissue equivalence.Because of its flexibility,good dose response and real-time readout characteristics,scintillation detector has been a hot topic in the measurement of complex dose distribution.The paper studies the water equivalent properties and radiation luminescence properties of three kinds of mixed materials composed of scintillator materials.A plastic scintillator based on the water equivalent of polystyrene and Zr O₂ was simulated.Monte Carlo program Geant4（GEometry And Tracking 4）was used to simulate X ray with different energy in the water,solid water RW34（2.1wt%Doped Polystyrene TiO₂）and polystyrene mixed with different concentrations of Zr O₂ particle energy depositing and transporting process,comparing dose and attenuation coefficient of different materials and water in different depth,finding mass fraction of ZrO₂ doped polystyrene when equivalent to water.The results show that the hybridization of0.4wt%ZrO₂ particles in polystyrene has good water equivalence and even better performance than RW34.A water-equivalent liquid scintillator was prepared by dodecylbenzene（LAB）,Triton X-100,Dimethyl sulfoxide（DMSO）,2,5-Diphenyloxazole（PPO）,1,4Bis（5-phenyloxazol-2-yl）benzene（POPOP）.Firstly,the empirical formula and Geant4 was used to calculate the best concentration ratio of the mentioned above materials with good water equivalence.According to the best concentration ratio,the liquid scintillators were prepared,and the water equivalent properties and radioluminescence properties of the materials were measured by biological X ray irradiator and multichannel spectrometer.The results show that the optimal formulation of new liquid scintillators for 1L is 0.09 L DMSO,0.36 L LAB,0.55 L Triton X-100,4g/L PPO and0.2g/L POPOP.At different energies of X-rays and at different depths,the absorption dose and dose ratio corresponding to water is about 0.9939⁰.9989,and it has good radiation characteristics,and its luminous efficiency is about 1/3 of the ULTIMA Gold^TMliquid scintillatos from the company of PE.A water-equivalent liquid scintillator was prepared by dodecylbenzene（LAB）,phenylmethylsiloxane oligomer（TPTMTS）,Triton X-100,2,5-Diphenyloxazole（PPO）,1,4Bis（5-phenyloxazol-2-yl）benzene（POPOP）Firstly,the empirical formula and Geant4 was used to calculate the best concentration ratio of the mentioned above materials with good water equivalence.According to the best concentration ratio,the liquid scintillators were prepared,and the water equivalent properties and radioluminescence properties of the materials were measured by small animal radiation therapy simulator and multichannel spectrometer.The results show that the optimal formulation of new liquid scintillators for 1L is 0.37 L TPTMTS,0.25 L LAB,0.55 L Triton X-100,4g/L PPO and 0.2g/L POPOP.At different energies of X-rays and at different depths,the absorption dose and dose ratio corresponding to water is about1.0041¹.0134,and it has good radiation characteristics,and its luminous efficiency is about 1.6 times of the ULTIMA Gold^TMliquid scintillatos from the company of PE.And it has better stability and luminous efficiency than the above liquid scintillator of LAB/DMSO/Triton X-100/PPO/POPOP system.In summary,this paper has found a method for designing water-equivalent scintillator materials,and successfully developed a water-equivalent liquid scintillator material,which solves the problem of detector equivalence.There are potential applications for environmental measurement,radiation protection,and dose measurement.