基于FPGA的复合晶体二维脉冲形状甄别系统

2-Dimension Pulse Shape Discriminatior for Phoswich Detector Based on FPGA

在数字化前后沿脉冲形状甄别[1]的基础上,对脉冲数据采集系统进行改进,将脉宽信息直接加入脉冲事例信息。由此将脉冲事例的处理分为在线粗处理和离线精确处理:在线时设置一个偏大的阈值,只存储此阈值以下的事例信息;离线对获取的数据进行处理,得到脉冲幅度与脉冲宽度谱,根据谱的具体形状,设置精确的甄别阈进行事例判选。该设计很好地解决了复合晶体温度变化引起的甄别阈变化问题,同时能够对甄别系统本身在小幅度处的失真进行校正,提高了甄别系统的准确性。

It improves the data acquire system for the pulse signal based on digital front-rear pulse shape discrimination system.It adds pulse width information into the pulse＇s data package.Base on this,we divide the pulse event process into two process,on line coast process and offline accurate process： the online process sets a big threshold,just save the data of the event below this threshold;the offline process uses the acquired data,get the pulse amplitude and pulse width,and then according the spectrum＇s real shape,set the accurate threshold.This design resolves the problem that the detector＇s decay time change with the temperature;at the same time,it can correct the system＇s distortion when the input signal at small amplitude,improves the discrimination system＇s accuracy.