Barros Suelen F, Vanin Vito R, Malafronte Alexandre A, Maidana Nora L, Martins Marcos N
Instituto de Física, Universidade de São Paulo, Rua do Matão 1371, Cidade Universitária, CEP 05508-090, São Paulo, SP, Brazil.
J Synchrotron Radiat. 2018 Mar 1;25(Pt 2):484-495. doi: 10.1107/S1600577517018318. Epub 2018 Feb 15.
Dead-time effects in X-ray spectra taken with a digital pulse processor and a silicon drift detector were investigated when the number of events at the low-energy end of the spectrum was more than half of the total, at counting rates up to 56 kHz. It was found that dead-time losses in the spectra are energy dependent and an analytical correction for this effect, which takes into account pulse pile-up, is proposed. This and the usual models have been applied to experimental measurements, evaluating the dead-time fraction either from the calculations or using the value given by the detector acquisition system. The energy-dependent dead-time model proposed fits accurately the experimental energy spectra in the range of counting rates explored in this work. A selection chart of the simplest mathematical model able to correct the pulse-height distribution according to counting rate and energy spectrum characteristics is included.
在计数率高达56 kHz的情况下，当光谱低能端的事件数超过总数的一半时，研究了使用数字脉冲处理器和硅漂移探测器采集的X射线光谱中的死时间效应。研究发现，光谱中的死时间损失与能量有关，并提出了一种考虑脉冲堆积的针对此效应的解析校正方法。此模型和常用模型已应用于实验测量，通过计算或使用探测器采集系统给出的值来评估死时间分数。所提出的与能量相关的死时间模型准确拟合了本工作所探索计数率范围内的实验能谱。文中还给出了一个根据计数率和能谱特征校正脉冲高度分布的最简单数学模型的选择图表。
