Doing Science Underground

We operate our experiments underground laboratories to reduce the impact of cosmic rays, muons, and other high-energy particles that naturally emanate from space. This is crucial for studying rare and elusive processes, such as neutrinoless double-beta decay, which has a half-life greater than 10^26 years. Such experiments require a very low background that is well modeled, and high detection efficiency and sensitivity. Cosmogenic activation leads to further backgrounds and thus requires our experiments to be built and operated underground.

The LEGEND experiment is operated underground at Laboratori Nazionali del Gran Sasso in Italy. The 1400-meter rock burden above the laboratory provides a cosmic ray flux reduction by one million times, and the Dolomite calcareous rock of the mountain provides lower levels of uranium and thorium background. Underground, the detectors are heavily shielded and handled in a low background environment to further reduce the naturally occurring radioactive backgrounds.

At UNC, we operate two cleanrooms that enable us to maintain a clean environment and perform the production of clean components as well as research and development for experiments without going underground. The lab has a glove box that allows for an ultra-clean environment for detector and support materials and has equipment for sensitive operations such as wire bonding and precision cable stripping. We also have a dedicated wet-lab cleanroom that allows for the chemical cleaning of parts, and we have developed strict cleanliness protocols to ensure the highest level of background reduction.