Observations of the Askaryan Effect in Ice

TL;DR

This paper presents the first direct observation of the Askaryan effect in ice, confirming theoretical predictions and supporting the use of ice in ultra-high energy neutrino detection experiments.

Contribution

First experimental detection of the Askaryan effect in ice, validating its use for neutrino detection in ice-based experiments like ANITA.

Findings

Observation of coherent impulsive radio Cherenkov radiation in ice

Results consistent with theoretical expectations

Supports ice as a viable medium for neutrino detection

Abstract

We report on the first observations of the Askaryan effect in ice: coherent impulsive radio Cherenkov radiation from the charge asymmetry in an electromagnetic (EM) shower. Such radiation has been observed in silica sand and rock salt, but this is the first direct observation from an EM shower in ice. These measurements are important since the majority of experiments to date that rely on the effect for ultra-high energy neutrino detection are being performed using ice as the target medium. As part of the complete validation process for the Antarctic Impulsive Transient Antenna (ANITA) experiment, we performed an experiment at the Stanford Linear Accelerator Center (SLAC) in June 2006 using a 7.5 metric ton ice target, yielding results fully consistent with theoretical expectations.