Theia is a potential multi-purpose, large-scale neutrino detector in its very early design stages. It aims to utilize water-based liquid scintillator or lightly-doped oil as a detector medium coupled with very fast timing to study a broad physics program. Its prospects include the capability to detect and measure neutrinos over a very broad energy spectrum, with the potential to deduce the hierarchical nature of neutrinos, measure the level of CP violation in the lepton sector and potentially determine whether the neutrino is Majorana in nature. Furthermore, Theia will be able to study neutrinos from multiple sources including the Earth’s core, the Sun, galactic supernovae, and the diffuse flux of cosmological supernova neutrinos.
In Greek Mythology, Theia is a Titan and often connected with the gift of light and heavenly sight for humans. Her consort/brother is Hyperion, also a Titan. Together they are the parents of Helios (the Sun), Selene(the Moon), and Eos (the Dawn).
Advanced Scintillation Detector Concept (ASDC)
Theia is a realization of the possibility described in arXiv:1409.5864 of a detector that would make use of recent advances in liquid scintillators and fast photosensors to make a 50 kiloton scale optical detector with sub-Cherenkov threshold light detection at low energy, enhanced particle tracking at GeV energies, and loading with isotopes for double beta decay and solar neutrino physics. This detector builds on the phenomenal success of conventional organic liquid scintillator detectors such as KamLAND and Borexino (and soon SNO+) by scaling up the size and resolution, and locating it at deep depth (likely the new Long Baseline Neutrino Facility (LBNF) at SURF.