Pure cesium iodide(CsI) crystal and the CsI crystal doped with thallium(Tl) or sodium(Na) ions are good scintillation crystals forγray and X ray detection. As a scintillator it could be made into elements with various shapes for different application. The dimension of elements could be millimeters and up to length of 350 mm and diameter of 120 mm. The crystal arrays coupled with photodiode are widely used in the apparatus for security inspection in airport and sea port. Its scintillation emission spectrum curves and scintillation properties are shown in the figure and table. There are photos shown the apparatus using CsI arrays for luggage and container inspection.

Scintillation Properties of CsI(Tl),CsI(Na), CsI Crystal