Study of luminescence characteristics of CsI:Br and CsI:Pb scintillator crystals grown by Bridgman technique

Inorganic scintillators having a short decay time (about ten ns), high density and high light yield have being studied for applications in the high energy physics, nuclear tomography and other fields of science and engineering. CsI-based scintillation crystals are considered promising materials for these applications, because they exhibit a high plasticity, a relatively low hygroscopicity and a low cost. These characteristics make them suitable to be used as detectors of ionizing radiation under hard operation conditions, such as heavy mechanical and thermal loading. This paper describes the preparation of the pure CsI, CsI:Br and CsI:Pb grown, using the Bridgman technique, varying the concentration of the Br from 10-1 to 1x10-2 mole and the Pb from 10-2 to 10-3 mole. The dopant composition were analyzed by chemical and optical methods. A good uniformity of the Br dopant distribution over the height was observed inside each ingot. To evaluate the crystals obtained, systematic measurements of optical transmittance, emission spectra, pulse heights and luminescence decay curves were carried out. The pure CsI crystal was grown and is luminescence characteristics were evaluated for comparison. (author)