Feasibility of a Next Generation Underground Water Cherenkov Detector: UNO
Chang Kee Jung
TL;DR
UNO targets a next-generation large-volume water Cherenkov detector to enhance nucleon decay searches and precision neutrino measurements. The proposed design is a linear, compartmentalized 3-module detector totaling ~650 kton (fiducial ~445 kton), with a central high-coverage region for low-energy solar neutrinos and supernova neutrinos and wings for broader physics programs, enabling significant gains in sensitivity and statistics. Preliminary cost estimates place construction around $520M (baseline) to $680M (full coverage), with feasibility supported by existing technology, cost-scaling analyses, and site options such as WIPP, NM; no critical R&D barriers are identified. UNO would deliver an order-of-magnitude improvements in nucleon decay sensitivity, tens to hundreds of thousands of supernova neutrino events, high-precision solar/atmospheric neutrino data, and potential compatibility as a far detector for future neutrino facilities, making it a versatile, multi-purpose cornerstone for US high-energy physics.
Abstract
The feasibility of a next generation underground water Cherenkov detector is examined and a conceptual design (UNO) is presented. The design has a linear detector configuration with a total volume of 650 kton which is 13 times the total volume of the Super-Kamiokande detector. It corresponds to a 20 times increase in fiducial volume for physics analyses. The physics goals of UNO are to increase the sensitivity of the searches for nucleon decays about a factor of ten and to make precision measurements of the solar and atmospheric neutrino properties. In addition, the detection sensitivity for Supernova neutrinos will reach as far as the Andromeda galaxy.