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
$1.99 \pm 0.02~\mu\hbox{s}$
at room temperature under
$^{137}{\rm Cs}\gamma $
-ray excitation. The CsI:In light yield was found to be
$34,700 \pm 1735$
photons per MeV with an energy resolution of
$9.1 \pm 0.3\% $
, based on the pulse height spectra under
$^{137}{\rm Cs}$
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.