Performance of scintillation materials at cryogenic temperatures

TL;DR

This paper reviews the performance of various scintillation materials at cryogenic temperatures, highlighting recent advances, understanding of mechanisms, and their suitability for rare event detection in physics experiments.

Contribution

It provides a comprehensive overview of scintillator properties at low temperatures, including new insights into their mechanisms and performance limits for rare event search applications.

Findings

CaWO4, CdWO4, and Bi4Ge3O12 have near-theoretical maximum light yields at low temperatures.

Progress in material preparation improves scintillation efficiency at cryogenic temperatures.

Different materials offer specific advantages and limitations for cryogenic phonon-scintillation detectors.

Abstract

An increasing number of applications of scintillators at low temperatures, particularly in cryogenic experiments searching for rare events, has motivated the investigation of scintillation properties of materials over a wide temperature range. This paper provides an overview of the latest results on the study of luminescence, absorption and scintillation properties of materials selected for rare event searches so far. These include CaWO4, ZnWO4, CdWO4, MgWO4, CaMoO4, CdMoO4, Bi4Ge3O12, CaF2, MgF2, ZnSe and AL2O3-Ti. We discuss the progress achieved in research and development of these scintillators, both in material preparation and in the understanding of scintillation mechanisms, as well as the underlying physics. To understand the origin of the performance limitation of self-activated scintillators we employed a semi-empirical model of conversion of high energy radiation into light and made appropriate provision for effects of temperature and energy transfer. We conclude that the low-temperature value of the light yield of some modern scintillators, namely CaWO4, CdWO4 and Bi4Ge3O12, is close to the theoretical limit. Finally, we discuss the advantages and limitations of different materials with emphasis on their application as cryogenic phonon-scintillation detectors (CPSD) in rare event search experiments.