Speaker
Description
Detecting particles that interact only weakly with matter, such as dark matter, and studying materials under the absence of cosmic background radiation require extremely low-noise environments. SNOLAB achieves this by operating 2 km underground, providing one of the world’s deepest laboratories for studying rare-event phenomena and sensitive quantum technologies. However, even at such depths, background radiation from ambient neutrons remains a significant challenge. These neutrons are primarily produced by the spontaneous fission of U-238 and (α,n) reactions in the surrounding rock. Their interactions can mimic rare-event dark matter signals and affect the study of superconducting qubits. This research aims to measure the underground neutron flux spectrum at SNOLAB to improve our understanding of the background environment and enable better signal discrimination. The Arktis S670e helium-4 scintillation detector is used to measure both fast and thermal neutrons. SOURCES-4C was used to estimate the neutron energy spectrum based on the local rock composition, followed by detector modelling in Geant4. The detector was deployed in the J-Drift and Low Background Laboratory, where data were collected and analyzed to study its response to gamma-ray and neutron sources of different energies. By characterizing the detector's response, this work lays the foundation for measuring the underground neutron energy spectrum in future studies.
| What area of study best describes your talk? | Hardware / Hands-on |
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