ID 112413
Author
Ejiri, Hiroyasu Osaka University
Hazama, R Osaka Sangyo University
Ikeda, H Tohoku University
Imagawa, K I.S.C. Lab.
Inoue, K Tohoku University
Kanzaki, G Tokushima University
Kozlov, A The University of Tokyo
Shima, T Osaka University
Takemoto, Y The University of Tokyo
Teraoka, Y Tohoku University
Umehara, S Osaka University
Yasuda, K I.S.C. Lab.
Yoshida, S Osaka University
Content Type
Journal Article
Description
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 μBq/kg and 1.5±1.9 μBq/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 μBq/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.
Journal Title
Journal of Physics: Conference Series
ISSN
17426596
17426588
NCID
AA12839617
Publisher
IOP Publishing
Volume
718
Start Page
042022
Published Date
2016-06-09
Rights
Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
EDB ID
DOI (Published Version)
URL ( Publisher's Version )
FullText File
language
eng
TextVersion
Publisher
departments
Science and Technology