Research About The Control System In The Performance Calibration System Of Two-Dimensional Neutron Detector

China Spallation Neutron Source project(abbreviation CSNS) whose first part is expected to be completed in 2017 ~ 2018 is at Dalang town Dongguan city.After completion,the project will be the fourth biggest neutron source in the world,playing an important role in promoting original innovation, basic research and application research of china.The neutron detector performing well is the key equipment of the project.With better performance of the new neutron devices,the neutron detectors based on new scintillator and photoelectric readouts are in rapid development in recent years, so CSNS will use a number of two-dimensional neutron detectors whose ZnS(Ag) scintillator is doped with 6Li. In order to ensure the consistency of all neutron detectors, a calibration system for the performance of two dimensional neutron detector is designed, so in this paper the main discussion is about the electronic control system of the calibration system.In the neutron detector, the photon produced from the impaction of the neutron and the scintillation goes to the PMT through the wave-length shift fiber.Then the photon will be processed by the electronic system,transforming the optical signal to electric signal. The purpose of this project is to calibrate the performance parameters of the segments from the wavelength shift fiber to the PMT with analog pulse light,including following aspects:1) the core controller based on embedded system, the controller communicates with the the smart pulse signal generator and 2D platform through FPGA, communicates with the environment parameter acquisition module through the RS485 bus,communicates with PC through the TCP/ IP;2) the smart pulse signal generator controlled by the core controller can produce signal whose frequency,duty ratio,amplitude is variable,the pulse signal drives the laser diode(LD)to produce pulse light. 3) the two-dimensional mobile platform controlled by the core controlle:the pulse light source which is located on the two-dimensional platform goes to the wave length shift fiber through the optical fiber. 4) the realization of system, the host computer(PC) sent instructions to the core controller through TCP/IP,controlling two-dimensional mobile platform and the pulse light source, receiving the signal from neutron detector electronics system and the signal of the environment parameters, processing data,automatically calibrating the performance parameters such as detection efficiency of effective position, spatial resolution, total counting rate of the detector(2D).This thesis firstly discusses the necessity of the performance calibration system of two dimensional neutron detector, putting forward the requirements of the control system in thecalibration system and the overall design of the system; then discusses the core controller design basing on STM32 and FPGA, TCP/IP and RS485 interface circuits; and then discusses the process of generating pulse light,including the pulse signal based on FPGA and the analog signal generated by the DAC8512 and the pulse signal whose frequency, pulse width,amplitude is variable;then discusses the control system of the two-dimensional mobile platform based on the stepper motor and the feedback from themagnetic grating ruler; finally discusses the realization of the control system of two-dimensional neutron detector,and after test, the control system can perfectly meet all requirements.