Table 1.

Main features of the CsI(Tl) scintillator material.

Property	Value
density	4.51 g/cm3
<Z>	54
attenuation coefficient at 662 keV	0.36 cm−1
light yield	60,000 photons/MeV
energy resolution @ 662 keV	5–10% FWHM
primary decay constant	960 ns
λ max emission	550 nm
refractive index @ emission max	1.79
cost of 1 × 1 × 1 cm3 crystal	≈EUR 30