Development of Hexagonal Radio Array for the ARIANNA Ultra-High Energy Neutrino Detector

University Of California-Irvine, Irvine CA

Investigators

Abstract

The primary purpose of the ARIANNA Ultra-High Energy (UHE) Neutrino project is to observe about 40 cosmogenic neutrinos per year from the GZK mechanism - extragalactic UHE protons collide with cosmic microwave background photons, producing pions that eventually decay to neutrinos - with sufficient precision to determine their energy spectrum and interaction properties. The energy spectrum of cosmogenic neutrinos provides important insight on the production mechanism and source distribution of cosmic rays. ARIANNA relies on the detection of radio pulses generated in dense media by the Askaryan effect and capitalizes on several properties of the Ross Ice Shelf near McMurdo Station, the hub of US operations: (1) the ice is impressively transparent to electromagnetic radiation at radio frequencies, (2) the water-ice boundary below the shelf behaves like a good mirror to reflect radio signals from neutrinos in any downward direction and (3) background noise levels are quite modest in the frequency band of interest. Nearby Minna Bluff protects the site from significant anthropogenic radio noise. Its close proximity to McMurdo Station provides a number of suitable options for logistical support. This award will fund the next step toward the realization of the ARIANNA concept, called the Hexagonal Radio Sub-array: to construct, deploy and commission a hexagonal arrangement of 7 autonomous detector stations at the ARIANNA site to assess large-scale feasibility, system robustness and the ambient noise environment over an extended period of time. These tests will provide input to optimize the final design of the Phase A component of ARIANNA, which consists of a 12 x 12 array of stations Among the broader impacts of this project are an outlet for curiosity and imagination driven research by students who will be given the opportunity to learn about data acquisition electronics, detector simulation, and data processing.