A new low background laboratory in the Pyhäsalmi mine: Towards 14C free liquid scintillator for low energy neutrino experiments

Abstract

A new low background laboratory in Pyhäsalmi mine in the Central Finland has been put into operation in the beginning of 2017. The laboratory operates at the depth of 1436 m (∼4100 meters of water equivalent). In this paper, we present description of the laboratory's existing facility and background conditions. In the laboratory, a series of measurements has been started where the 14C concentration is determined from several liquid scintillator samples. A dedicated setup has been designed and constructed with the aim of measuring the 14C/12C ratio smaller than 10-18.