Development of the NUCLEUS Detector to Explore Coherent Elastic Neutrino-Nucleus Scattering

The NUCLEUS experiment, currently being commissioned at the Technical University of Munich, is designed to observe coherent elastic neutrino-nucleus scattering (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow...

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Bibliographic Details
Main Author: Nicole Schermer
Format: Article
Language:English
Published: MDPI AG 2025-01-01
Series:Particles
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Online Access:https://www.mdpi.com/2571-712X/8/1/8
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Summary:The NUCLEUS experiment, currently being commissioned at the Technical University of Munich, is designed to observe coherent elastic neutrino-nucleus scattering (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>CE</mi><mi>ν</mi><mi>NS</mi></mrow></semantics></math></inline-formula>) from reactor neutrinos and measure its cross-section with a percent-level precision at recoil energies below <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>100</mn><mo> </mo><mrow><mi>eV</mi></mrow></mrow></semantics></math></inline-formula>. As a Standard Model process, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>CE</mi><mi>ν</mi><mi>NS</mi></mrow></semantics></math></inline-formula> provides a unique probe into neutrino properties, potential new physics, and background suppression techniques relevant to dark matter experiments. The experiment utilizes gram-scale cryogenic calorimeters operating at <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>10</mn><mo> </mo><mrow><mi>mK</mi></mrow></mrow></semantics></math></inline-formula> with an energy threshold of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>20</mn><mo> </mo><mrow><mi>eV</mi></mrow></mrow></semantics></math></inline-formula>. Situated at a shallow overburden of 3 m of water equivalent, the experimental site necessitates an advanced shielding strategy combining active vetoes and passive layers to reduce background rates to approximately <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>100</mn><mspace width="0.166667em"></mspace><mrow><mi>counts</mi><mo>/</mo><mo>(</mo><mi>kg</mi><mspace width="0.166667em"></mspace><mo>·</mo><mspace width="0.166667em"></mspace><mi>day</mi><mspace width="0.166667em"></mspace><mo>·</mo><mspace width="0.166667em"></mspace><mi>keV</mi><mo>)</mo></mrow></mrow></semantics></math></inline-formula>, as confirmed by full setup simulations. The commissioning phase has successfully demonstrated the stable operation of the cryogenic target detectors, achieving baseline resolutions below <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>10</mn><mo> </mo><mrow><mi>eV</mi></mrow></mrow></semantics></math></inline-formula>, and the integration of the various shielding systems. Following this milestone, the experiment is set to transition to the EdF Chooz B nuclear reactor in France in 2025, where it will enable precise measurements of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>CE</mi><mi>ν</mi><mi>NS</mi></mrow></semantics></math></inline-formula>, contributing to the understanding of neutrino interactions and advancing the field of astroparticle physics.
ISSN:2571-712X