TY - JOUR
T1 - Dark matter search project PICO-LON
AU - Fushimi, K.
AU - Ejiri, H.
AU - Hazama, R.
AU - Ikeda, H.
AU - Imagawa, K.
AU - Inoue, K.
AU - Kanzaki, G.
AU - Kozlov, A.
AU - Orito, R.
AU - Shima, T.
AU - Takemoto, Y.
AU - Teraoka, Y.
AU - Umehara, S.
AU - Yasuda, K.
AU - Yoshida, S.
N1 - Publisher Copyright:
© Published under licence by IOP Publishing Ltd.
PY - 2016/6/9
Y1 - 2016/6/9
N2 - 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.
AB - 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.
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U2 - 10.1088/1742-6596/718/4/042022
DO - 10.1088/1742-6596/718/4/042022
M3 - Conference article
AN - SCOPUS:84981294235
SN - 1742-6588
VL - 718
JO - Journal of Physics: Conference Series
JF - Journal of Physics: Conference Series
IS - 4
M1 - 42022
T2 - 14th International Conference on Topics in Astroparticle and Underground Physics, TAUP 2015
Y2 - 7 September 2015 through 11 September 2015
ER -