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Author(s)
| Ferrulli, F (U. Caen (main) ; CERN) ; Caresana, M (Milan, Polytech.) ; Cova, F (Milan Bicocca U.) ; Gundacker, S (CERN) ; Kratochwil, N (CERN ; Vienna U.) ; Pots, R (CERN) ; Silari, M (CERN) ; Vedda, A (Milan Bicocca U.) ; Veronese, I (Milan U. ; INFN, Milan) ; Zorloni, G (CERN ; Milan, Polytech.) |
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Abstract
| $^7$Li enriched Cs$_2$LiYCl$_6$:Ce$^{3+}$ (CLYC) is a promising inorganic scintillator for real-time γ-ray and fast neutron
spectrometry. The neutron/γ-ray discrimination is usually accomplished exploiting the different quenching
effects of high Linear Energy Transfer (LET) particles on different scintillation mechanisms, usually by
means of the time analysis of the pulse shape. In principle, the emission wavelength information could be
used to address the same task. However, a systematic study of the correlations between the CLYC decay
time, its radio-luminescence spectrum and the LET of the impinging particle has not yet been performed.
We therefore investigated the CLYC scintillation process under neutron and γ-ray irradiation, correlating the
time response to the scintillation wavelength spectrum using a 1–inch right cylinder > 99% $^7$Li enriched
CLYC. We found that the relative intensity of the Core to Valence Luminescence (CVL) is almost constant
with photons in the energy range 20–660 keV, i.e. 0.5–5 keV/μm LET, and is only partially quenched by
neutrons. Instead, the direct electron-hole capture scintillation mechanism is completely cut under neutron
irradiation. The luminescence in between the deep-Ultraviolet and the Near Ultraviolet region
(250–350 nm) might be attributed to both the CVL and the host luminescence, also in thick highly Ce$^{3+}$-doped crystals. |