Sodium Iodide Nal (TI)
Scintillation Crystal Detectors 
NaI (Tl) is a super performance scintillation crystal. The crystal is grown from pure NaI
raw material doped with thallium. The maximum emission is up to 415nm, which is
well matched to the sensitivity curve of photomultiplier tubes (PMTs) with bialkali
photocathodes.
The material has very high luminescence efficiency, and exhibits no
significant self absorption of the scintillation light and has good resolution ability to Xray
and γ‐ray. 
NaI (Tl) crystals are widely used in Military application, Oilfield
exploration, Metallurgy, Social security, Environmental control, Medical detection,
Physical research, etc.
Main Properties
| Density |
3.67 g/cm3 |
| Mohs hardness |
2.1 |
| Melting point |
651℃ |
| Thermal expansion coefficient |
47.4 x 10-6 K-1 |
| Cleavage plane |
(100) |
| Light yield |
38 x 103 Photons / MeV γ |
| Wavelength of emission maximum |
415 nm |
| Primary decay constant |
250 ns |
| Refractive index at emission max. |
1.85 |
