A description of a procedure for selecting events during the absorption of stopped pions in thin targets is presented. This approach is based on the use of two monitor Si-detectors and a “live” target, which is also an Si-detector, as the last layers of the moderator. Setting the thresholds on monitor detectors and analyzing signals from a “live” target allow one to select pions with a residual range corresponding to the target thickness and reliably exclude the background from stops in the monitor system. It is shown that this method provides an efficiency of identifying stopped π^–-mesons of 90%.

中文翻译：

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π-介子核吸收反应事件的选择

介绍了在薄目标中吸收停止的π介子过程中选择事件的过程。这种方法基于使用两个监控硅探测器和一个“实时”目标，它也是一个硅探测器，作为调节器的最后一层。设置监测探测器的阈值并分析来自“实时”目标的信号，可以选择剩余范围与目标厚度相对应的π介子，并可靠地排除监测系统中停止点的背景。结果表明，该方法提供了90%的识别停止的 π ^-介子的效率。