DETERMINATION OF THALLIUM DISTRIBUTION IN CsI (TI) CRYSTALS WITH X-RAY FLUORESCENCE SPECTROSCOPY

摘要

Thallium activated cesium iodide Cs(TI)crystals are now used in large detectors. In the past several years,a large amount of CsKTDcrystals were grown by Bridgman Stock-barger process and tested in our institute in order to provide high quality crystals for European and Japan high energy physical laboratories. Despite the heterogeneous distribution of thallium in the whole crystal ,it was shown that the uniformity of Csl (Tl)crystals was satisfactory when the average content of Tl reached 400 μg/g or so. As a quality control process,it was important to sampling to determine Tl and its distribution in the crystals for every batch of product. Beklemishev et al determined Tl in Nal(TI) crystal with XRF by solvent extraction of Tl.