Scintillation Properties of Cs2NaLaI6:Ce

In this paper we present results on our initial study of Ce doped Cs₂NaLaI₆ scintillator. The crystals of this material belong to the elpasolite family characterized by a cubic structure and potentially can be easily grown in large volumes. The crystal has density of 4.2 g/cm³ (estimated) and effective atomic number of 54.4. Under X-ray excitation the samples show blue emission that extends from 400 to 500 nm with two peaks at 429 and 461 nm. The emission is due to the d-f transitions on Ce³⁺ ions. Scintillation is fast and can be described with 55 to 63 ns decay time constant when fit with a single exponent. Slower component are also observed. A few nanosecond rise time is rather slow and depends on Ce concentration. The best light output of the investigated samples was ~46, 000 photons/MeV. Although the crystals were somewhat milky relatively good energy resolution of 5.0% at 662 keV was measured. With fully transparent samples we expect it to improve, taking into account extremely good non-proportionality results.