Dark matter search with high purity NaI(Tl) scintillator

TL;DR

This paper reports the development and testing of a highly radiopure NaI(Tl) scintillator for dark matter detection, achieving extremely low background levels essential for rare event searches.

Contribution

The authors developed a new purification method for NaI(Tl) crystals, significantly reducing radioactive contaminants for dark matter experiments.

Findings

Achieved $^{ ext{nat}}$K and $^{210}$Pb levels below 20 ppb and 5.7 μBq/kg.

Designed and tested a prototype detector module with high-purity crystals.

Demonstrated potential for large-scale dark matter search experiments.

Abstract

A dark matter search project needs and extremely low background radiation detector since the expected event rate of dark matter is less than a few events in one year in one tonne of the detector mass. The authors developed a highly radiopure NaI(Tl) crystal to search for dark matter. The best combination of the purification methods was developed, resulting $^{\mathrm{nat}}$K and $^{210}$Pb were less than 20 ppb and 5.7 $\mu$Bq/kg, respectively. The authors will construct a large volume detector system with high-purity NaI(Tl) crystals. The design and the performance of the prototype detector module will be reported in this article.