Simulation And Experimental Study Of Optical Luminescence Detection System

Optically Stimulated Luminescence（OSL）was first discovered by Przibram et al.in the early 20th century.It gradually replaced traditional thermosluminescence（TL）technology and is widely used in geological sample detection and archaeological dating.In recent years,along with the continuous expansion of OSL detection technology in archaeological,medical dose,environmental dose,personal dose and other fields in China,higher requirements have been put forward for advanced radiation dose detection technology.Therefore,the in-depth study of OSL dose measurement technology has broad application prospects.This thesis is aimed at measuring the radiation dose in the environment.Based on a large number of domestic and foreign related literatures,this thesis introduced the basic principles of OSL detection technology,analyzed the characteristics of OSL materials,selected Al₂O₃:C as OSL detection material according to project requirements,and determined the principle scheme of the OSL fluorescence detection system.An experimental system was built and the fluorescence spectrum of Al₂O₃:C was measured by a high sensitivity fiber spectrometer.By analyzing the spectral curve data,the center wavelength of the fluorescence spectrum excited by Al₂O₃:C material was estimated as 414.9nm,which verifies the exponential decay relationship of the OSL intensity with time.The spectral absorption efficiency of Al₂O₃:C material was measured experimentally.The optical simulation software ASAP was used to simulate the designed principle scheme of detection.The main optical components such as laser,fiber,fiber coupler and detector in the OSL fluorescence detection system were established respectively,and the simulation calculation was carried out.The influence of the main technical indexes of each component on the simulation results was analyzed.It was concluded that under the same conditions,the scheme of the normal incidence of the excitation light is better than that of the scheme with a certain angle of incidence,and the spot size and enegy distribution are better controlled.The attenuation coefficient of the fluorescence transmission process using optical fiber was calculated,which provides reference data for long-distance dose detection design.The power of the OSL material Al₂O₃:C fluorescence light was calculated,which provides a reliable basis for the selection of photodetectors and the design of subsequent signal processing circuits.The feasibility of the designed OSL dose detection system was verified by the simulation,which provides theoretical guidance for further experimental design.