Characterization of CsI:Tl at a wide temperature range (−40 °C to +22 °C)

The aim of this work is the characterization of a ∅ 9×9 mm CsI:Tl scintillator at a wide temperature range of −40 °C to +22 °C. A tested crystal with dimensions of ∅ 9×9 mm was coupled to a 16 mm diameter large area Avalanche photodiode (LAAPD). The crystal and the LAAPD were cooled down in a cryostat with a built-in Peltier element. Properties such as the number of electron–hole pairs per 1 MeV, the nonproportionality, the energy resolution and the intrinsic resolution were inspected with eight different peaking times – i.e., 0.6 μs, 1.2 μs, 2.4 μs, 4.8 μs, 7.2 μs, 9 μs, 14.4 μs, 28.8 μs – and discussed in terms of the light pulse shapes measured by a single photon method.