Design of the constant fraction of pulse height trigger for optimum time resolution

Abstract

The constant fraction of pulse height trigger has been shown previously1,2 to provide the optimum time resolution with a scintillator-photomultiplier system. The principle is discussed in detail in this paper and a circuit suitable for general use is presented. Over a 100: 1 dynamic range the walk is within ± 120 psec. The lower threshold is variable from 0.8 mA to 10 mA on the anode pulse height. A comparison is made with other commonly used timing methods. © 1968.