Underground Muon Flux Experiment beside LUX-ZEPLIN Dark Matter Detector — 66a — Andy Freeman, Ashley Marines

The LUX-ZEPLIN (LZ) dark matter detector at the Sanford Underground Research Facility (SURF) in Lead, SD is one of the world’s most sensitive dark matter detection experiments. The experiment is run within the Davis Cavern, which is nearly a mile underground to help shield the detector from cosmic rays which constantly penetrate Earth’s surface. Muons are a part of this shower of particles, a very small fraction of which are expected to traverse the near mile of Earth’s crust and produce a signal in the LZ detector. Information of the muon flux at the LZ detector is important for the classification of signals produced. 

A months-long muon flux experiment was started directly adjacent to the detector in the Davis Cavern. The QuarkNet Cosmic Ray Detector (QNCRD), originally designed for use on the surface, was used. This detector allows for raw data files with GPS validity to be uploaded to the internet and analyzed. The detector needed to be modified, as it did not have capabilities of establishing a steady GPS connection from a mile underground. A python script with the ability to reconstruct the GPS, time, and date information of each event and write over the existing raw data file was developed and implemented. All other raw muon detection data were preserved. This allowed for the long-term use of the QNCRD in the Davis Cavern. 

This experiment aims to establish a value for total muon flux at the LZ detector in the Davis Cavern after a few months of data collection. Data will be uploaded to the internet for public access.

Black Hills State University
Ellie Bishop, Brianna Mount