An Experiment to Demonstrate Separation of Cherenkov and Scintillation Signals

TL;DR

This paper demonstrates a novel detector design capable of separating Cherenkov and scintillation signals, which could significantly advance neutrino detection by enabling directional, low-threshold measurements.

Contribution

The paper introduces an innovative detector setup and calibration methods that successfully reconstruct Cherenkov rings in scintillating media, showing promising separation capabilities.

Findings

Cherenkov rings reconstructed in water target

Time precision of 338 +/- 12 ps achieved

High Cherenkov hit identification efficiency predicted

Abstract

The ability to separately identify the Cherenkov and scintillation light components produced in scintillating mediums holds the potential for a major breakthrough in neutrino detection technology, allowing development of a large, low-threshold, directional detector with a broad physics program. The CHESS (CHErenkov / Scintillation Separation) experiment employs an innovative detector design with an array of small, fast photomultiplier tubes and state-of-the-art electronics to demonstrate the reconstruction of a Cherenkov ring in a scintillating medium based on photon hit time and detected photoelectron density. This paper describes the physical properties and calibration of CHESS along with first results. The ability to reconstruct Cherenkov rings is demonstrated in a water target, and a time precision of 338 +/- 12 ps FWHM is achieved. Monte Carlo based predictions for the ring imaging sensitivity with a liquid scintillator target predict an efficiency for identifying Cherenkov hits of 94 +/- 1% and 81 +/- 1% in pure linear alkyl benzene (LAB) and LAB loaded with 2 g/L of PPO, respectively, with a scintillation contamination of 12 +/- 1% and 26 +/- 1%.