Development Of Real-time Monitoring System Of High Radiation Dose Based On Al₂O₃:C

With the rapid development of nuclear technology and the increasing number of people engaged in radioactive work,hence the task of radiation monitoring is becoming more and more important.However,in some high-dose workplace,such as radiation therapy,hot rooms,irradiation processing plants,etc.,existing dose monitoring systems still have some shortcomings.Long-term strong radiation will damage electronic components located in the radiation field.By combining with the fiber optic technology,some scintillators or optically stimulated luminescence materials can be made into a fiber optic probe that is placed in a radiation field,and radioluminescence signal is transmitted through the optical fiber to the electronic measuring instrument that's away from the radiation field,which can effectively solve the dose monitoring challenges in high dose facility.Therefore,for the radiation monitoring problem in high-dose workplace,this paper designs a radiation dose real-time monitoring system based on carbon-doped alumina?Al₂O₃:C?crystals,which can effectively monitor real-time dose rate and measure cumulative dose in high radiation background.This paper relies on National Natural Science Foundation of China:high-resolution aerial gamma spectroscopy and 3D quantitative inversion techniques?41774190?,The main research contents and achievements of this paper are as follows:?1?Research on the principle of dose measurement in real-time monitoring system.Based on the theory of solid energy band,the characteristics of the photoluminescence signal and the radiation signal generated by Al₂O₃:C crystal were analyzed.The principle of Al₂O₃:C for radiation dose monitoring was also studied.?2?Design and development of the hardware part of the high-dose real-time monitoring system.The design of the hardware system.According to the relevant theoretical calculations,the selection basis of each component equipment is detailed;at the same time,the optical path design,band pass selection,amplification circuit,data acquisition,etc.are studied.Based on the dose monitoring principle of Al₂O₃:C crystal,this paper successfully built a prototype of high-dose real-time monitoring system.?3?Signal processing and software development of high-dose real-time monitoring system.For real-time dose rate monitoring and cumulative dose measurement,this paper studies the methods of radioluminescence and optically stimulated luminescence signal processing of Al₂O₃:C crystal.On this basis,the system software architecture and design was completed,and the control software of the dose monitoring system was developed based on the WINDOWS environment.The software is mainly composed of a user management interface,a main control interface,a system parameter setting interface and a result analysis interface,and realizes the functions of real-time dose rate and cumulative dose joint measurement.?4?Performance testing and application research of high-dose real-time monitoring system.The prototype of the high-dose real-time monitoring system was verified by a miniature X-ray tube.The test results show that there is a good linear relationship between the radioluminescence signal and the radiation dose rate.The linear fitting coefficient R² of the two filters is 0.9995,so the prototype has the ability to monitor the radiation dose rate in real time.And the test results show that there is a good linear relationship between the optically stimulated luminescence signal and accumulation dose,and the linear fit coefficient R² of the results of two filters is 0.9851.The prototype has cumulative dose measurement capability.The number of filters affects the lower limit of the real-time dose rate detection and the time it takes for the radiant luminescence signal to stabilize.Based on Al₂O₃:C crystals,a real-time monitoring system for high-radiation backgrounds was developed.There is a good linear relationship between the radioluminescence signal and the dose rate,and there is a good linear relationship between optically stimulated luminescence signal and the cumulative dose,which indicating that the system has real-time dose rate and cumulative dose joint measurement function,and it is expected to be used in high-dose sites such as radiation therapy,hot rooms,and irradiation processing plants.