Measurement of acoustic properties of South Pole ice for neutrino astronomy

TL;DR

This paper reports on the measurement of acoustic properties of South Pole ice using SPATS, assessing its suitability for neutrino detection through acoustic, optical, and radio methods, with initial results on sound speed, noise, and attenuation.

Contribution

It presents the deployment, performance, and initial findings of SPATS, a novel system for evaluating ice properties relevant to acoustic neutrino detection at the South Pole.

Findings

Initial measurements of sound speed in ice

Background noise levels characterized

Attenuation properties of ice studied

Abstract

South Pole ice is predicted to be the best medium for acoustic neutrino detection. Moreover, ice is the only medium in which all three dense-medium detection methods (optical, radio, and acoustic) can be used to monitor the same interaction volume. Events detected in coincidence between two methods allow significant background rejection confidence, which is necessary to study rare GZK neutrinos. In 2007 and 2008 the South Pole Acoustic Test Setup (SPATS) was installed as a research and development project associated with the IceCube experiment. The purpose of SPATS is to measure the acoustic ice properties at the South Pole in order to determine the feasibility of a future large hybrid array. The deployment and performance of SPATS are described, as are first results and work in progress on the sound speed, background noise, and attenuation.