NS21B-1921
Measurement Over Large Solid Angle of Low Energy Cosmic Ray Muon Flux

Tuesday, 15 December 2015
Poster Hall (Moscone South)
Henry Fredrick Schreiner III and Roy F Schwitters, University of Texas at Austin, Austin, TX, United States
Abstract:
Recent advancements in portable muon detectors have made cosmic ray imaging practical for many diverse applications. Working muon attenuation detectors have been built at the University of Texas and are already successfully being used to image tunnels, structures, and Mayan pyramids.
Most previous studies have focused on energy measurements of the cosmic ray spectrum from of 1 GeV or higher. We have performed an accurate measurement of the ultra-low energy (<2 GeV in E cos θ) muon spectrum down to the acceptance level of our detector, around one hundred MeV. Measurements include angular dependence, with acceptance approaching horizontal. Measurements were made underwater using a custom enclosure in Lake Travis, Austin, TX.
This measurement will allow more accurate predictions and simulations of attenuation for small (<5 m) targets for muon tomography.