Algorithm for Determination of Arrival Time of Signals from the Liquid Xenon Calorimeter of CMD-3 Detector

In CMD-3 detector the n– $$\bar {n}$$ pair production events can be detected only by the calorimeters where a large energy deposition from antineutron annihilation occurs. For identification of such events it is necessary to determine the arrival time of the calorimeter signals with accuracy of several nanoseconds. Preliminary estimations have shown that the required time resolution can be obtained only basing on signals of the liquid‑xenon calorimeter. The shapes of the liquid‑xenon calorimeter’s output electric signals differ substantially from event to event, thus an additional error is added to the measured signal arrival time even when a constant‑fraction discriminator is used. For measuring the arrival time of the liquid‑xenon calorimeter’s signals a special digital signal processing algorithm has been developed which allows one to reduce the error of signal arrival time determination added by the difference of signals' shapes. In this paper the developed algorithm is described and the results obtained after optimization of this algorithm on the real events data are presented.