核脉冲数字基线改进算法

Nuclear pulse digital baseline improvement algorithm

由于CR微分电路引起的下冲经数字模拟转换器(Analog-to-digital Converter,ADC)转换后的信号基线漂移现象一直存在,增加了数字基线估计算法的复杂度,影响了在线基线的实时性与准确性。通过对平均值法实时提取随机波形信号数字化基线算法的研究,提出了一种在现场可编程门阵列(Field-Programmable Gate Array,FPGA)可实现的核脉冲数字基线改进算法——平均值阈值法。采用实测的一个带下冲信号进行拆解拼接后得到一条基线值固定的新信号,经平均值阈值法求得的基线与该拼接信号的基线值一致,并且当基线值发生变化时,该算法实时跟随效果好。平均值阈值法实时提取随机波形信号数字化基线算法能有效的计算出基线,并且占用内存小,计算速度快,经该算法处理后的基线值稳定性好,具有较强的跟随效果。

[Background] After the analog-to-digital converter (ADC) conversion, the baseline drift caused by CR differential circuit always exists. It increases the complexity of digital baseline estimation algorithm, and affects the real-time and accuracy of online baseline.[Purpose] This study aims to improve the average method for extracting the digital baseline algorithm of random waveform signals in real-time.[Methods] An improved method of nuclear pulse digital baseline named average threshold method that can be implemented in field-programmable gate array (FPGA) was proposed. A measured signal with undershoot was taken as simulation nuclear pulse signal by disassembling and splicing to obtain a new signal with a fixed baseline value.[Results] The baseline obtained by the average threshold method was consistent with the splicing baseline value. This algorithm exhibited strong real-time tracking effect while the baseline was changing.[Conclusion] The average threshold method for real-time extraction of random waveform signals digital baseline algorithm can effectively calculate the baseline with less memory occupation and quick speed. The baseline value processed by the algorithm is stable, has a strong follow-up effect.