CsI(Na) has the main properties of the CsI matrix (good stopping power, relatively soft and plastic material without cleavage plane), but has a wavelength of emission peak at 420nm. This wavelength is well matched to the photocathode sensitivity of a bialkali photomultiplier and has a light output of 85% of NaI(Tl). Compared to NaI(Tl), the material interesting where severe environmental conditions are encountered.
Suitable for standard PMT readout
CsI(Na) is hygroscopic and must be hermetically sealed. Basic detector designs offered are: a packaged scintillator, a scintillator integrally mounted to a light sensor and a scintillator with a demountable PMT. The ultimate end-use and performance specifications determine crystal size, housing material, optical window material, light-sensing device, and electonics.
Standard size is between 1” diameter x 1” to 3” diameter x 3”, but length up to 12” can be manufactured
|Melting point [K]||894|
|Thermal expansion coefficient [C-1]||54 x 10-6|
|Wavelength of emission max. [nm]||420|
|Lower wavelength cutoff [nm]||300|
|Refractive index @ emission max||1.84|
|Primary decay time [ns]||630|
|Light yield [photons/keVγ]||41|
|Photoelectron yield [% of NaI(Tl)] (for γ-rays)||85|