Research On X-ray Multi-channel Pulse Amplitude Analysis System

The X-ray multi-channel pulse amplitude analysis system is a key technology for ray energy spectrum measurement,which plays an important role in many basic scientific researches.In this paper,the corresponding X-ray pulse signal acquisition system and digital signal processing and analysis system are designed according to the law of X-ray transmission medium attenuation.The X-ray multi-channel pulse amplitude analysis system designed this time includes hardware circuits and signal extraction algorithms and software.The design of the hardware circuit part includes power supply circuit,signal conditioning circuit,analog-to-digital conversion circuit,FPGA main control circuit and UART interface circuit.The power supply circuit provides effective power supply voltage to the hardware circuits of the entire X-ray multi-channel pulse amplitude analysis system;the signal conditioning circuit performs direction amplification processing on the output signal of the X-ray detector,which is convenient for the analog-to-digital conversion circuit to convert the analog pulse signal into digital Signal;FPGA main control circuit controls the hardware circuit of the entire system and processes digital pulse signals;UART interface circuit completes data communication processing with the host computer.The software program part adopts a top-down modular design method to structure the internal logic of FPGA,and uses Verilog HDL language to complete the functions of pulse analysis and data communication on FPGA.Software design includes simplified algorithm implementation of ladder-shaped filter algorithm,implementation of ladder-shaped filter algorithm in Matlab simulation software,implementation of trapezoidal filter simplified algorithm in FPGA,pulse discrimination and peak detection module design,pulse analysis module and other digital signal processing modules Design and design of each data communication module.After completing the construction of the X-ray multi-channel pulse amplitude analysis system,the modules of the system were tested.The absolute error of the measurement of the AD sampling circuit is within ±1m V.The maximum relative error of the test results of the trapezoidal filter module is about 3% when there is no noise,and about 5% when the noise is added.The implementation time of the algorithm in FPGA is 4us.The relative error of the test results of the pulse discrimination and peak detection module is about 1%.The test results ofthe pulse analysis module show that the maximum pass rate is 150 KHz,and the pulse channel address is linearly related to the amplitude of the input signal.The final overall system test results show that the system has good digital information processing capabilities and its comprehensive performance reaches the expected target.