Temperature dependence on counting efficiency of NE213 liquid scintillator for low level neutron measurements

The measurement of neutron energy spectra is important to elucidate the mechanism of cold fusion phenomena. Many reports have shown that the neutron counting rate in the foreground measurement was as low level as the background in studies of cold fusion. We have measured neutron energy spectra in an electrolysis experiment over a long time by a liquid scintillator NE213 with a gamma-neutron pulse shape discrimination to detect 2.45 MeV neutrons. We found the counting rate of the detector decreases with temperature rises in the detector. The temperature dependence for measurements of very weak level neutrons under the temperature difference between foreground and background measurements needs to be clarified. This is a report of the temperature dependence on the counting efficiency for the NE213 system. (author)