Design and performance of a Compton-coincidence system for measuring non-proportionality of new scintillators

A Compton-coincidence scintillator light yield non-proportionality measurement system was constructed and tested. Improved testing procedures and timing resolution have allowed the use of significantly less active excitation sources without lengthening test times or degrading data integrity. Previous methods typically required 100 mCi Cs-137 sources, but an increase in solid angle between source and sample as well as improved timing resolution have allowed the use of sources with activities less than 10 μCi. Representative samples of BGO and NaI(Tl) were tested to validate the system against literature single-source data.