基于双指数拟合的核信号堆积脉冲重构方法

Nuclear Pile-Up Pulse Reconstruction Method Based on Double-Exponential Fitting

摘要: 高计数率下核脉冲信号容易发生堆积，将堆积脉冲直接舍弃的方法会导致能谱计数率的下降。本文用硅漂移探测器对X光管激发的铜合金样品进行测量，采用14位20 MHz的ADC采样获取数据，在Matlab上对输出信号进行冲激成形以识别堆积脉冲，应用双指数表达式对堆积脉冲进行重构并进行幅值提取计入能谱中。结果表明，与传统的直接舍弃堆积脉冲相比，该方法提高了能谱计数，提升率约为21.37%。

Abstract: Nuclear pulse tend to pile up at high count rate. The traditional method is to discard the pile-up pulse, which will decrease the energy spectrum count rate. In this paper, silicon drift detector is used to measure the copper alloy excited by X-ray tube, 14-bit 20 MHzADC is used to obtain the data, impulse pulse-shaping is performed on Matlab to identify the pile-up pulse of the output signal, and the pile-up pulse is reconstructed by double-exponential expression and the amplitude is extracted and included in the energy spectrum. The results show that, compared with directly rejecting the pile-up pulse, this method improves the energy spectrum count by 21.37%.