An adaptive digital filter for quasi-Gaussian pulse shaping
An adaptive digital filter for quasi-Gaussian pulse shaping
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DOI：
10.1088/1748-0221/18/04/p04002
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发表时间：
2023-04
影响因子：
1.3
通讯作者：
Xu Hong;Lin Li;Junlong Wu;Xiaoyan Yang
中科院分区：
文献类型：
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作者：
Xu Hong;Lin Li;Junlong Wu;Xiaoyan Yang
辐射探测器的输出常常被整形成高斯或准高斯形状，以提高测量性能。提出了一种用于准高斯脉冲整形的自适应数字阶跃高斯滤波器。它既适用于指数衰减输入，也适用于阶跃输入。建立了该滤波器的传递函数。与PZC-(RC)n滤波器和CR-(RC)n滤波器的幅频特性进行了比较。结果表明，该滤波器具有与PZC-(RC)n滤波器相同的幅频特性，具有比CR-(RC)n滤波器更有效的滤波性能。搭建了一套基于FAST-SDD探测器的X射线荧光测量系统进行实验。利用锰样品产生的测量脉冲对所提出的滤波器进行了验证。滤波器输出的形状表明，阶跃-高斯滤波器可以消除CR-(RC)n滤波器输出中存在的下冲。建立了不同整形时间的振幅谱，研究了特征峰的形状。结果表明，阶跃高斯滤波可以消除5.89keV能量峰的低能拖尾。并引入峰形参数FWTM/FWHM来评价峰形改善效果。与CR-(RC)n滤光片相比，阶跃高斯滤光片产生的5.89keV谱峰更接近于高斯分布。
The radiation detector output is often shaped into Gaussian or quasi-Gaussian shape to improve the measurement performance. An adaptive digital Step-Gaussian filter is presented for quasi-Gaussian pulse shaping in this paper. It can be applied for both exponential decay input and step input. The transfer function of the filter is established. The amplitude-frequency features of the new filter are compared with the PZC-(RC) n filter and the CR-(RC) n filter. The results indicate that the new filter has the same amplitude-frequency features as the PZC-(RC) n filter and it possesses more effective filter performance than the CR-(RC) n filter. An X-ray fluorescence measurement system based on a FAST-SDD detector is set up for experiments. The proposed filter is verified by the measured pulses that are generated from a manganese sample. The shape of the filter output shows that the Step-Gaussian filter can eliminate the undershoot that exists in the CR-(RC) n filter output. The amplitude spectrums with different shaping times are created to study the shape of the characteristic peak. The results show that the Step-Gaussian filter can cancel the low-energy peak tailing of the 5.89 keV peak. The peak shape parameter, FWTM/FWHM ratio, is also introduced to evaluate the performance of peak shape improvement. The 5.89 keV peaks of the spectrums that are generated by using Step-Gaussian filter are closer to Gaussian distribution than that of the CR-(RC) n filter.