Theia is a proposed large-scale novel neutrino detector, designed with the ability to discriminate between Cherenkov and scintillation signals.
The design consists of a cylindrical tank viewed by inward-looking PMTs and filled with a novel target, such as water based liquid scintillator (WbLS) or other scintillator, which would allow simultaneous reconstruction of particle direction from the Cherenkov signal, with the energy resolution and low threshold of a scintillator detector.
Theia would have a broad physics program ranging from low energy solar to high energy accelerator neutrinos.