# The $\nu$-cleus experiment: A gram-scale fiducial-volume cryogenic detector for the first detection of coherent neutrino-nucleus scattering

## TL;DR

The $
u$-cleus experiment aims to detect coherent neutrino-nucleus scattering using a small, cryogenic, gram-scale detector with ultra-low energy thresholds, enabling new physics insights and practical nuclear monitoring.

## Contribution

It introduces a novel, low-threshold cryogenic detector design capable of detecting neutrino interactions at unprecedented low energies, with active background discrimination.

## Key findings

- Achieved a 20 eV energy threshold in a prototype detector
- Demonstrated potential for neutrino detection at nuclear reactors within two weeks
- Showed feasibility of real-time nuclear power plant monitoring

## Abstract

We discuss a small-scale experiment, called $\nu$-cleus, for the first detection of coherent neutrino-nucleus scattering by probing nuclear-recoil energies down to the 10 eV-regime. The detector consists of low-threshold CaWO$_4$ and Al$_2$O$_3$ calorimeter arrays with a total mass of about 10 g and several cryogenic veto detectors operated at millikelvin temperatures. Realizing a fiducial volume and a multi-element target, the detector enables active discrimination of $\gamma$, neutron and surface backgrounds. A first prototype Al$_2$O$_3$ device, operated above ground in a setup without shielding, has achieved an energy threshold of ${\sim20}$ eV and further improvements are in reach. A sensitivity study for the detection of coherent neutrino scattering at nuclear power plants shows a unique discovery potential (5$\sigma$) within a measuring time of ${\lesssim2}$ weeks. Furthermore, a site at a thermal research reactor and the use of a radioactive neutrino source are investigated. With this technology, real-time monitoring of nuclear power plants is feasible.