Crystal growth and characterization of europium doped KCaI3, a high light yield scintillator

• Single crystal growth and characterization of a high performance ternary halide scintillator.
• Spectroscopic performance comparisons of small and large crystals.
• 3% energy resolution at 662 keV and ≈72,000 ph/MeV for a small crystal.

The presented study reports on the spectroscopic characteristics of a new high performance scintillation material KCaI3:Eu. The growth of ∅ 17 mm boules using the Bridgman–Stockbarger method in fused silica ampoules is demonstrated to produce yellow tinted, yet transparent single crystals suitable for use in spectroscopic applications due to very promising performance. Scintillation light yield of 72,000 ± 3000 ph/MeV and energy resolution of 3% (FWHM) at 662 keV and 6.1% at 122 keV was obtained from small single crystals of approximately 15 mm3. For a much larger 3.8 cm3 detector, 4.4% and 7.3% for the same energy. Proportionality of the scintillation response to the energy of ionizing radiation is within 96% of the ideal response over an energy range of 14–662 keV. The high light yield and energy resolution of KCaI3:Eu make it suitable for potential use in domestic security applications requiring radionuclide identification.