Acoustic neutrino detection in sea water: Technical aspects

The acoustic neutrino detection technique is a promising approach for future large-scale detectors with the aim of measuring the small expected flux of ultra-high-energy cosmogenic neutrinos. This article focuses on the technical aspects of the application of this technique in water. Though the technique is intriguingly simple, challenges arise from e.g. anisotropic sound propagation, ambient noise or transient background in a natural environment. We present major technical aspects of acoustic neutrino detection based on experience gained with different acoustic test arrays. Before aiming for a largescale acoustic or hybrid (opto-acoustic) detector, the acoustic detection technique needs to be investigated further in the next generation of Cherenkov neutrino telescopes that are currently prepared. We discuss the technical implementation into those large optical detectors, primarily focussing on the KM3NeT project.