Design of the Second-Generation ARIANNA Ultra-High-Energy Neutrino Detector Systems

TL;DR

This paper describes the development of the second-generation ARIANNA neutrino detector array in Antarctica, featuring advanced radio sensing stations designed to detect ultra-high-energy cosmogenic neutrinos with high precision and low power consumption.

Contribution

The paper introduces a new station design with a synchronous SST chip, improved trigger sensitivity, and autonomous power systems for large-scale neutrino detection.

Findings

Successful deployment of seven stations in Antarctica

Achieved high trigger sensitivity and low power consumption

Demonstrated effective autonomous operation in harsh environment

Abstract

We report on the development of the seven station ARIANNA Hexagonal Radio Array neutrino detector systems in Antarctica. The primary goal of the ARIANNA project is to observe ultra-high energy (>100 PeV) cosmogenic neutrino signatures using a large array of autonomous stations each dispersed 1 km apart on the surface of the Ross Ice Shelf. Sensing radio emissions of 100 MHz to 1 GHz, each station in the array contains RF antennas, amplifiers, a 2 G-sample/s signal acquisition and trigger circuit I.C. (the "SST"), an embedded CPU, 32 GB of solid-state data storage, a 20 Ah LiFePO4 battery with associated battery management unit, Iridium short-burst messaging satellite and long-distance WiFi communications. The new SST chip is completely synchronous, contains 4 channels of 256 samples per channel, obtains 6 orders of magnitude sample rate range up to 2 GHz acquisition speeds. It achieves 1.5 GHz bandwidth, 12 bits RMS of dynamic range, ~1 mV RMS trigger sensitivity at >600 MHz trigger bandwidth and ps-level timing accuracy. Power is provided by the sun and LiFePO4 storage batteries, and the second-generation stations consume an average of 4W of power. The station's trigger capabilities reduce the trigger rates to a few milli-Hertz with 4-sigma thresholds while retaining high efficiency for neutrino signals.