基于随机抽样的核脉冲信号发生器的研究

Research on Nuclear Pulse Signal Generator Based on Random Sampling

本文设计了一种基于FPGA的任意核能谱脉冲信号发生器。该脉冲信号发生器以32位随机数发生器为基础,通过对参考谱线在幅度上的抽样,使输出脉冲信号在幅度上满足参考谱线的概率密度分布函数。系统对脉冲出现的时间进行1 024区间分割,并计算得到不同分割区间内脉冲信号出现的概率及该时间间隔的平均时间,采用随机抽样使输出脉冲信号在时间上满足指数分布规律。实际测试结果表明:该信号发生器输出脉冲在计数率上满足泊松分布,在幅度上满足参考谱线的概率密度分布函数;系统噪声低于2.86mV;输出脉冲计数率可调,满足核脉冲信号的规律。

An arbitrary nuclear spectrum pulse signal generator based on FPGA was presented in this paper.With this pulse signal generator based on 32 bit random number generator,output pulse signal could meet probability density function of the reference spectrum in pulse amplitude by sampling from reference spectrum in pulse amplitude.In the meanwhile,the system could finish interval segmentation of 1 024 for the time of pulse appearing.Then the appearance probability of pulse signal in different intervals and the average time between time intervals were calculated.By random sampling,the output pulse signal could meet the law of exponential distribution in time.The practical test result shows that the pulse which is outputted by this signal generator can meet the Poisson distribution in count rate,and can meet probability density function of thereference spectrum in pulse amplitude as well.The system noise is less than 2.86 mV,and the output pulse count rate could be adjusted,which meet the law of nuclear pulse signal.