Redundant Timing Crosschecking for Frontend Digitization Systems: Principle and Validation Tests

In contemporary high energy physics experiments, in addition to the regular three dimensions, the fourth dimension, or the timing information of the charged particle hits becomes necessary. It would be very useful for the frontend digitization system to include a feature of redundant timing crosschecking. The inspiration for the timing crosschecking scheme came from the long-abandoned analog mean-timer schemes. In this mean time based scheme, a cable set with taps connected to the digitization modules is utilized as a pulse path and pulses are driven from both ends alternately without overlapping. The mean times of arrival times of the pulses in different modules represent a common time standard and their variations is recorded and monitored. The time delay drifts of the cable segments are self-cancelled in this scheme and this feature enables easy achievement of good timing precision without need for complex hardware.