(University of Chicago)
Directional Liquid Scintillator Detector for Neutrinoless Double-Beta Decay
Observation of neutrinoless double-beta decay (0νßß-decay) would establish
that the neutrino is a Majorana particle. I will briefly review the history, experimental challenges, and current status of searches for this rare nuclear process. I
will then discuss an idea of using fast photo-detectors in a large liquid scintillator
detector to search for 0νββ-decay.
Selection of early photons using fast photo-detectors separates prompt direc-
tional Cherenkov light from delayed isotropic scintillation light. Electrons from
0νββ-decay are often exceed Cherenkov threshold in liquid scintillator. This
leads to the possibility to reconstruct event topology of 0νßß-decay candidate
events by analyzing spatial distribution of early photons.
Using a simulation of 6.5 m radius liquid scintillator detector with 100 ps
resolution photo-detectors, I will show that a spherical harmonics analysis of
early photons provides a discriminating power between two track 0νßß-decay
and single track 8B solar neutrino event topologies.
Large-Area Picosecond Photo-Detector (LAPPD™) is an attractive option
of photo-detector with sufficient time resolution. LAPPD™ is a 20×20 cm2
thin, planar, glass-body detector with two Micro-Channel Plates in a chevron
geometry with 8º bias angle. With a complete detector system approximating
the detector design, we have measured a gain of up to 2×107
of-flight resolution of ∼60 ps, differential time resolution of ∼5 ps, and spatial
resolution of better than 1 mm in two dimensions. I will conclude by discussing
the development of LAPPD™.