Studies of the responses of liquid and solid targets for direct dark matter searches

The quenching factor for sodium recoils in a 2-inch Nal(Tl) scintillating crystal has been measured at room temperature. The crystal has been exposed to 2.45 MeV monoenergetic neutrons generated by a deuterium-deuterium fixed target accelerator in the energy range 10 to 100 keV nuclear recoil energy. A BC501A liquid scintillator detector has been used to tag neutrons that scatter off sodium nuclei in the crystal. Cuts on pulse shape discrimination in BC501A and neutron time of flight have been performed on pulses recorded by an Acqiris DC265 digitiser with a 2 ns sampling time. A quenching factor of 25.2 ± 6.4% has been determined for 10 keV sodium recoils. Measured quenching factors range from 19% to 26% in good agreement with other experiments. From pulse shape analysis, the mean time of pulses from electron and nuclear recoils have been compared down to 2 keV electron equivalent energy.EThOS - Electronic Theses Online ServiceGBUnited Kingdo