Measuring the 14C content in liquid scintillators

[摘要] We are going to perform a series of measurements where the14C/12C ratio will be measured from several liquid scintillator samples with a dedicated setup. The setup is designed with the aim of measuring ratios smaller than 10-18. Measurements take place in two underground laboratories: in the Baksan Neutrino Observatory, Russia and in the Pyhäsalmi mine, Finland. In Baksan the measurements started in 2015 and in Pyhäsalmi they start in the beginning of 2015. In order to fully understand the operation of the setup and its background contributions a development of simulation packages has also been started. Low-energy neutrino detection with a liquid scintillator requires that the intrinsic14C content in the liquid is extremely low. In the Borexino CTF detector at Gran Sasso, Italy the14C/12C ratio of 2 × 10-18has been achieved being the lowest14C concentration ever measured. In principle, the older the oil or gas source that the liquid scintillator is derived of and the deeper it situates, the smaller the14C/12C ratio is supposed to be. This, however, is not generally the case, and the ratio is probably determined by the U and Th content of the local environment.

[发布机构] Oulu Southern Institute, Department of Physics, University of Oulu, Finland^1;Institute for Nuclear Research, Russian Academy of Sciences, Moscow, Russia^2;Department of Physics, University of Jyväskylä, Finland^3

[效力级别] 天文学 [学科分类] 天文学(综合)

[关键词] Finland;Gas sources;Liquid scintillator;Local environments;Low energy neutrinos;Simulation packages;Underground laboratory