Determination of Thallium Doping in Cesium Iodide Scintillator Crystals

Advisor: Bill Lynch ABSTRACT The light output of CsI(Tl) scintillators must be tested prior to their use in the HiRA. Various experimental techniques are described as part of an attempt to determine the thallium doping in these scintillator crystals. Results for doping concentrations are given for several different crystals, and preliminary graphs of normalized light output versus normalized thallium doping presented. However, the thallium doping and light output are not independent of measurement techniques and there are considerable fluctuations in the data. More work is necessary to explore these discrepancies and resolve them. Work will continue after this report is submitted. INTRODUCTION The National Superconducting Cyclotron Laboratory at Michigan State University is building a High Resolution Array (HiRA) in collaboration with the Chemistry Department of Indiana University and Washington University in St. Louis, MO. When completed, the HiRA will be used to detect lighter charged particles (Z<10) produced in nuclear reactions. The HiRA will consist of 20 telescopes, each made up of two