Particle identification by pulse-height correlation in a range telescope

Abstract

A range telescope consisting of 22 plastic scintillators was constructed to aid in the identification of photoproduced K mesons with energies between 175 and 300 MeV. Extensive use of the correlation between pulse heights helped establish the particle identification. After preselection of a fairly standard nature, pulse heights from 18 scintillators were digitized and punched onto paper tape for subsequent computer analysis. Data from the last few counters were used to establish a range for the particle under a particular mass hypothesis, and it was required that these data represent a reasonable behavior for the stopping particle. Using this range and mass, a parameter similar to χ 2 was then computed from the data from the remaining counters. From the distribution of this variable, backgrounds and efficiencies were estimated. The method permitted a gain of about a hundred in rejection efficiency over pure electronic selection. Various backgrounds, phototube instabilities and computing difficulties limited the technique, but it was successful for this experiment and may have other uses.