Dark matter search project PICO-LON

K. Fushimi, H. Ejiri, R. Hazama, H. Ikeda, K. Imagawa, K. Inoue, G. Kanzaki, A. Kozlov, R. Orito, T. Shima, Y. Takemoto, Y. Teraoka, S. Umehara, K. Yasuda, S. Yoshida

Research output: Contribution to journalConference articlepeer-review

23 Citations (Scopus)


The PICO-LON project aims at search for cold dark matter by means of highly radio-pure and large volume NaI(Tl) scintillator. The NaI powder was purified by chemical processing to remove lead isotopes and selecting a high purity graphite crucible. The concentrations of radioactive impurities of 226Ra and 228Th were effectively reduced to 58 ± 4 μ Bq/kg and 1.5 ± 1.9 μ Bq/kg, respectively. It should be remarked that the concentration of 210Pb, which is crucial for the sensitivity to dark matter, was reduced to 24 ± 2 μ Bq/kg. The total background rate at 10 keVee was as low as 8 keV-1kg-1day-1, which was sufficiently low to search for dark matter. Further purification of NaI(Tl) ingot and future prospect of PICO-LON project is discussed.

Original languageEnglish
Article number42022
JournalJournal of Physics: Conference Series
Issue number4
Publication statusPublished - 2016 Jun 9
Event14th International Conference on Topics in Astroparticle and Underground Physics, TAUP 2015 - Torino, Italy
Duration: 2015 Sept 72015 Sept 11


Dive into the research topics of 'Dark matter search project PICO-LON'. Together they form a unique fingerprint.

Cite this