Prospects for high-elevation radio detection of 0>10 PeV tau neutrinos

Abstract

Tau neutrinos are expected to comprise roughly one third of both the astrophysical and cosmogenic neutrino flux, but currently the flavor ratio is poorly constrained and the expected flux at energies above 10 17 eV is low. We present a detector concept aimed at measuring the diffuse flux of tau neutrinos in this energy range via a high-elevation mountaintop detector using the radio technique. The detector searches for radio signals from upgoing air showers generated by Earthskimming tau neutrinos. Signals from several antennas in a compact array are coherently summed at the trigger level, permitting not only directional masking of anthropogenic backgrounds, but also a low trigger threshold. This design takes advantage of both the large viewing area available at high-elevation sites and the nearly full duty cycle available to radio instruments. We present trade studies that consider the station elevation, frequency band, number of antennas in the array, and the trigger threshold to develop a highly efficient station design. Such a mountaintop detector can achieve a factor of ten improvement in acceptance over existing instruments with 100 independent stations. With 1000 stations and three years of observation, it can achieve a sensitivity to an integrated E −2 flux of < 10 −9 GeV cm −2 sr −1 s −1 , in the range of the expected flux of all-flavor cosmogenic neutrinos assuming a pure iron cosmic-ray composition.

Modeling and Validating RF-Only Interferometric Triggering with Cosmic Rays for BEACON

“…We anticipate several extensions to the current Cranberry model. These improvements are being developed in parallel with the neutrino detector model for BEACON [6] and will therefore inform the development of the future observatory. One important feature of the Cranberry library is that we can extract full time-domain waveforms observed at the antennas of the BEACON prototype.…”

“…Phased arrays implemented at the trigger level improve the signal-to-noise ratio -thereby lowering trigger thresholds -and allow directional rejection of noise. The BEACON concept is described in greater detail in Reference [6].…”

Improving Radio Frequency Detectors using High Performance Programmable Logic

“…Such a phased array trigger is also part of the proposed IceCube-Gen2 [12], the Radio Neutrino Observatory [13] as well as RNO-Greenland [14] which is currently being installed. This is also leveraged for high-elevation detection of tau neutrinos with BEACON [15].…”

Toward High Energy Neutrino Detection with the Radar Echo Telescope for Cosmic Rays (RET-CR)

“…Detection of the low flux of neutrinos at energies beyond 10 16 eV requires technologies that can cover large detection volumes with a minimum of apparatus [1][2][3][4][5][6][7]. In this article, we will discuss a pathfinder experiment that uses the radar echo method, a radio-based technique that may compliment existing strategies and help to extend the energy range of detected neutrinos up beyond 10 PeV.…”