By SILSEF
In nuclear detector, the high refractive index of the scintillator crystals causes a large number of the produced UV-vis photons to remain trapped inside the crystal: therefore up to the 70% of the light produced is not collected by the photodetector. Also, the spatial resolution and the sensitivity of existing systems suffer from this low photons collection efficiency. SILSEF developed solutions with CERN: - Light extracting layers can be deposited/fabricated on the exit surface of the scintillator crystal in order to increase the number of photons extracted. - A possible light extraction layer is a nano-patterned thin film of a material with refractive index higher than the scintillator (n > 1,8) for LYSO: this diffraction grating is referred to as ‘photonic crystal’ (PhC).
