CsI(Na), CSI(TL), and pure Csl
Cesium iodine is often used as a scintillation crystal. Depending on the type of dopant used, other scintillation materials can be achieved:
Csl(Na), Csl(TI), and pure Csl. Each has its own characteristics.
Light output of other scintillators is determined
relative to that of NaI(Tl.), which is said to have a light
output of 100%. The light output of Csl(TI) is 47% that of
Nal(TI), whereas the luminescence efficiency of CsI(Na) is
similar to that of NaI(Tl).
The dependence of Csl(Na) on temperature is not
very significant, giving it an advantage in high temperature and
outer space environments. However, the luminescence decreases
quickly in low energy (less than 20 KeV) and hygroscopicity is
stronger than that of CsI(Tl).
Pure CsI crystal is much less hygroscopic than
CsI(Tl). Its emission consists of the fast intrinsic
luminescence (10ns). The light output is as large as 4oC,
6 % of Nal(TI), but the great advantage of this crystal is its
fast timing characteristics.