Cosmic Rays in Your Pocket

Daniel Whiteson
(UC Irvine)

The source of cosmic rays at ultra-high energy (1018eV) remains an enduring open question in physics, limited by our ability to capture these rare events. I will describe the motivations and current status of the CRAYFIS (Cosmic RAYs Found In Smartphones) experiment, which attempts a novel approach to observing such mysterious particles by repurposing the existing network of smartphones as a ground detector array. Extensive air showers generated by cosmic rays produce muons and high-energy photons, which can be detected by the CMOS sensors of smartphone cameras. I will describe the important remaining hurdles, current work, and realistic prospects.