| Space radiation particles can cause single event effect,total ionizing dose,and charging and discharging effect to spacecraft,which leads to spacecraft damage and even failure.Astronauts’ life and health are in danger,too.Higher requirements of space radiation detection technology are put forward with the deepening of national space activities.The task of traditional detection technology can be completed more efficiently through digital technology for detecting data analysis and processing.As a result,digital technology is more suitable for space requirements.First of all,in order to realize space radiation detection,the space radiation detector digital system is designed and built.Detector system includes modules like the scintillator probe,detector electronics,signal acquisition and processing,and offline data processing,etc.Digital system,which includes modules like pulse waveform digitization and following processing,is an important subsystem of detector system.In this paper,waveform digitization and trigger principle are studied.Data acquisition and processing system is debugged and tested,and digital system works normally.According to the need,two ways of digital system pattern including online and offline can be chosen.Second,the synchronization debugging of two boards is conducted with digitization hardware and synchronization software.The time delay between two units is measured aiming at the problem of time synchromization between two units of radiation detector.With a delay of the master-board unit clock phase,the synchronization between the master-slave boards with a total of 32 channels is realized.Space radiation detection system is tested on earth surface.With the energy calibration results,particle discrimination and energy spectrum of neutron source 252 Cf are analysed.The results of using GdO as neutron enhanced material are also compared.The off-line data processing method is studied,including the smoothing,fitting and filtering of digital pulse.The algorithm of off-line processing is designed and the program is realized.Finally,based on synchronization,the selection of real events through trigger time tag has been realized.Research on the time performance of detected particles is taken using digital signal multismoothing method.Digitial pulse shape analysis with the trailing edge constant ratio time is conducted.The discrimination between neutron and gamma is realized and FOM is 0.765. |
