Phased arrays: A strategy to lower the energy threshold for neutrinos

• Main Authors: Wissel Stephanie, Avva Jessica, Bechtol Keith, Chesebro Tyler, Cremonesi Linda, Gupta Anusha, Ludwig Andrew, Messino Wesley, Miki Christian, Nichol Ryan, Oberla Eric, Romero-Wolf Andrew, Saltzberg David, Schlupf Chandler, Shipp Nora, Varner Gary, Vieregg Abigail
• Format: Article
• Language: English
• Published: EDP Sciences 2017-01-01
• Series: EPJ Web of Conferences
• Online Access: https://doi.org/10.1051/epjconf/201713505007

In-ice radio arrays are optimized for detecting the highest energy, cosmogenic neutrinos expected to be produced though cosmic ray interactions with background photons. However, there are two expected populations of high energy neutrinos: the astrophysical flux observed by IceCube (~1 PeV) and the cosmogenic flux (~ 1017 eV or 100 PeV). Typical radio arrays employ a noise-riding trigger, which limits their minimum energy threshold based on the background noise temperature of the ice. Phased radio arrays could lower the energy threshold by combining the signals from several channels before triggering, thereby improving the signal-to-noise at the trigger level. Reducing the energy threshold would allow radio experiments to more efficiently overlap with optical Cherenkov neutrino telescopes as well as for more efficient searches for cosmogenic neutrinos. We discuss the proposed technique and prototypical phased arrays deployed in an anechoic chamber and at Greenland’s Summit Station.