ABSTRACT
The Tl-activated Nal and Csl crystals exhibit high scintillation efficiency. The rigorous calculation of that location is a complex problem. The location of energy levels for some cations have been simulated in terms of a simple electrostatic model. Three emission bands of CsI:Tl have been ascribed to electronic transitions from Jahn-Teller minima of various symmetries of the triplet exited states of Tl+ centers. Thallium halide crystals TIBr and T1C1 are promising candidates for application to nuclear physics as conductive detectors of ionizing radiation. Rare-earth or lanthanide series ions are excellent activators for many compounds. Cerium chloride is of interest as a scintillator material and as another object for investigation of physical processes in Ce-based systems. Study of the spectroscopic and scintillation properties of the vacuum and Czochralski grown YAP crystals has been carried out. The Gd and Lu ions are very unlikely to introduce both hole and electron traps in materials.
