Drilling deep in South Pole Ice

TL;DR

This paper discusses the challenges of drilling deep in Antarctic ice for ultra-high energy neutrino detection and proposes modern autonomous melting probes as a solution for efficient sensor deployment.

Contribution

It introduces a modern design concept for autonomous melting probes inspired by 50-year-old Greenland tests, enabling scalable deployment in Antarctic ice.

Findings

Assessment of hot water drilling limitations

Proposal of a modern autonomous melting probe design

Potential applications for calibration and detection

Abstract

To detect the tiny flux of ultra-high energy neutrinos from active galactic nuclei or from interactions of highest energy cosmic rays with the microwave background photons needs target masses of the order of several hundred cubic kilometers. Clear Antarctic ice has been discussed as a favorable material for hybrid detection of optical, radio and acoustic signals from ultra-high energy neutrino interactions. To apply these technologies at the adequate scale hundreds of holes have to be drilled in the ice down to depths of about 2500 m to deploy the corresponding sensors. To do this on a reasonable time scale is impossible with presently available tools. Remote drilling and deployment schemes have to be developed to make such a detector design reality. After a short discussion of the status of modern hot water drilling we present here a design of an autonomous melting probe, tested 50 years ago to reach a depth of about 1000 m in Greenland ice. A scenario how to build such a probe today with modern technologies is sketched. A first application of such probes could be the deployment of calibration equipment at any required position in the ice, to study its optical, radio and acoustic transmission properties.