Research On Calibration Of CZT Detectors For Lightning High-Energy Radiation Detectio

The calibration of lightning high-energy radiation detector provides data support for the research and development of space particle detector,and is the basis of lightning high-energy radiation detection project.The research of lightning high-energy radiation detection is in its infancy in China,and there are the following difficulties in the process of application and development: First,the mechanism of lightning and its high-energy radiation generation is still pending in the academic community,and there is no physical model that can fully describe all the physical characteristics of these phenomena;Second,China’s space particle detectors have a narrow detection energy range and low sensitivity;The third is how to design and build a ground calibration analysis system to provide general,efficient and reliable calibration experiment work for space probes.Aiming at the application scenario of lightning high-energy radiation detection,this paper establishes a theoretical simulation model of relativistic escaping electron avalanche and performs simulation calculation,and uses the energy threshold and other parameters obtained in the simulation,combined with the performance parameter requirements of photon characteristics under the background of lightning high-energy radiation obtained by the detector,as the basis for the design requirements of the calibration analysis system,and uses the built calibration system to carry out a series of multi-dimensional calibration experiments on a CZT detector,and finally processes and analyzes the calibration experiment data.The main work of this article is as follows:(1)Research on the theoretical mechanism of lightning high-energy radiation.A relativistic evading electron avalanche theory model(RREA)was established,and the relevant characteristic parameters of the lightning high-energy radiation model were obtained.Theoretically,a function that only considers the change of electric field intensity is obtained to calculate the avalanche distance constant,avalanche duration constant,and ratio of photon number to number of escaping electrons.In this way,theoretical calculations and comparative analyses can be carried out more easily.(2)Calibration system and calibration experiment design.According to the characteristics of photon energy,time and flow under the background of lightning highenergy radiation,the particularity of the calibration system and experimental design was clarified,and a calibration system was established,and multi-dimensional calibration experiments were carried out for zinc-cadmium tellurium(Cd Zn Te,CZT)detector,including the measurement of energy response,temperature peak drift,high count peak drift,detection efficiency,detector noise and other parameters of CZT detector.(3)Data processing and analysis of calibration experiments.According to the data processing and analysis method given by the principle of calibration experiment,the performance parameters such as energy resolution and dead time of the detector to be calibrated are obtained.It meets the design requirements of ground calibration system for lightning high-energy radiation detection,realizes the multi-dimensional calibration of the detector,and plays a basic role in the smooth development and implementation of China’s space science exploration mission.