Scintillation Characteristics of Indium Doped Cesium Iodide Single Crystal

Indium doped cesium iodide (CsI:In) single crystals were grown by the Bridgman method. A comparison study of the scintillation properties of our CsI:In and commercially available CsI:Tl single crystals was carried out, including scintillation decay time, energy resolution, non-proportionality, absolute light yield, and afterglow. Under X-ray excitation, the CsI:In emission corresponds to a symmetrical broad band centered at 545 nm. Its scintillation decay time is 1.99 ±0.02 μs at room temperature under ¹³⁷Csγ-ray excitation. The CsI:In light yield was found to be 34,700 ±1735 photons per MeV with an energy resolution of 9.1 ±0.3%, based on the pulse height spectra under ¹³⁷Cs excitation. The afterglow level of CsI:In over 130 ms after pulsed X-ray excitation was two orders of magnitude higher than that of CsI:Tl.