Application of the Monte-Carlo refractive index matching (MCRIM) technique to the determination of the absolute light yield of a calcium molybdate scintillator

作者：Alenkov V; Buzanov O A; Khanbekov N; Kornoukhov V N; Kraus H; Mikhailik V B^*; Shuvaeva V A

来源：Journal of Instrumentation, 2013, 8(06): P06002.

DOI：10.1088/1748-0221/8/06/P06002

• Scintillators, scintillation and light emission processes (solid, gas and liquid scintillators)
• Double-beta decay detectors
• Detector modelling and simulations I (interaction of radiation with matter, interaction of photons with matter, interaction of hadrons with matter, etc)

The use of (CaMoO)-Ca-40-Mo-100 in experimental searches for neutrinoless double beta decay (0 nu DBD) relies on knowledge of fundamental scintillation properties of the material. In this work we determine the absolute light yield of calcium molybdate using Monte-Carlo refractive index matching technique (MCRIM). The MCRIM technique is a combination of experiment and simulations that allows the absolute light yield of scintillators to be determined by taking into account effects of refraction, scattering and absorption in the material. The light collection efficiency of the scintillator-detector assembly was simulated using the ZEMAX ray-tracing software. By tuning the optical parameters of the scintillation crystal, a model was derived that gives good agreement with the experimental results. It is shown that the light collection efficiency of scintillators increases with transmittance and scattering due to an enhanced probability for photons to escape the crystal volume. Using MCRIM, the absolute light yield for the (CaMoO4)-Ca-40-Mo-100 scintillator was found to be 7.5 +/- 1.2 ph/keV at room temperature. Comparative measurements using a CaWO4 scintillator as a reference show good agreement with this result. In that way, the study demonstrated the potential of the MCRIM technique as a tool for quantitative characterization of scintillation materials.

• 出版日期2013-6