Measurement of the proton light response of various LAB based scintillators and its implication for supernova neutrino detection via neutrino–proton scattering

Abstract

The proton light output function in electronequivalent energy of various scintillators based on linear alkylbenzene (LAB) has been measured in the energy range from 1 MeV to 17.15 MeV for the first time. The measurement was performed at the Physikalisch-Technische Bundesanstalt (PTB) using a neutron beam with continuous energy distribution. The proton light output data is extracted from proton recoil spectra originating from neutron-proton scattering in the scintillator. The functional behavior of the proton light output is described successfully by Birks' law with a Birks constant kB between (0.0094 ± 0.0002) cm MeV −1 and (0.0098 ± 0.0003) cm MeV −1 for the different LAB solutions. The constant C, parameterizing the quadratic term in the generalized Birks law, is consistent with zero for all investigated scintillators with an upper limit (95 % CL) of about 10 −7 cm 2 MeV −2 . The resulting quenching factors are especially important for future planned supernova neutrino detection based on the elastic scattering of neutrinos on protons. The impact of proton quenching on the supernova event yield from neutrino-proton scattering is discussed.

Experiment to demonstrate separation of Cherenkov and scintillation signals

“…The targets are simulated using properties from [14,15,42,44,45]. The scintillation light yield is set to 1010 photons/MeV for LAB [44] and 10800 photons/MeV for LAB/PPO [15].…”

“…The ratio of created photoelectrons for the two sources of light was approximately 5 to 1 (scintillation to Cherenkov) for a 45 MeV electron created in the detector. Photon timing and charge was used for particle identification and to reconstruct vertex and angle information.…”

Getting the most from the detection of Galactic supernova neutrinos in future large liquid-scintillator detectors

“…where the uncertainty is also included [26]. The quench effects of positrons or electrons [27] are neglected in the current study.…”

“…Besides these normalization uncertainties, an energy-related uncertainty is included in the pES case by taking a 3% relative uncertainty on the Birks' constant k B of the proton quenching effect, where the central value of k B is taken as 9.8 × 10 −3 cm MeV −1 [26]. The quench effects of positrons or electrons [27] are neglected in the current study.…”

Reconstruction of Spallation Neutron Kinematics in Antineutrino Detectors

“…Middel panel: Sum of proton recoil energies after each neutron.The difference between the truth and reconstructed spectrum is due to the proton quenching of LAB based scintillators [6]. Right panel:The distance between neutron production site and effective proton recoil site(center of energy).…”