A versatile delayed coincidence system

Abstract A versatile delayed coincidence system is described. The apparatus incorporates new methods of time-scale calibration and walk correction, a supervisory fast coincidence, ADC's in the energy channels as well as in the time channel, and an on-line PDP-8 computer. A fairly complete description of the logic design, computer program facilities and performance is given. As evidence of satisfactory performance we report two lifetime measurements that are in excellent agreement with established values: • 207 Pb, first excited state: T 1 2 = (130.2±1.5) ps; • 35 Cl, 4.174 MeV level: T 1 2 = (−.5±3) ps.