北京谱仪中的飞行时间探测器,由48块桶部计数器和48块端盖计数器组成,每一块计数器都由塑料闪烁体通过光导耦合到光电倍增管,给出幅度和时间信息。桶部计数器是两端耦合输出,端盖计数器是一端耦合输出,这样,飞行时间探测器提供144路幅度信号和144路时间信号。在制备完每一块计数器后,以及将全部计数器都安装到谱仪中后,都需要检查每一块计数器的性能是否有变化,能否正常运行,在运行过程中还需监视每一块计数 The time-of-flight detector in the Beijing spectrometer consists of 48 barrel counters and 48 end caps, each of which is coupled by a plastic scintillator to a photomultiplier tube through a light guide to give amplitude and time information. The barrel counter is coupled at both ends and the end cap counter is coupled at one end so that the time-of-flight detector provides 144 amplitude signals and 144 time signals. After preparing each counter and after installing all the counters in the spectrometer, it is necessary to check whether each of the counters has a change in performance, whether it can operate normally or not, and to monitor each of the counters during operation