ar X iv : a st ro - p h / 07 03 44 2 v 1 1 6 M ar 2 00 7 Integration of Acoustic Neutrino Detection Methods into ANTARES

The ANTARES Neutrino Telescope [1] is a water Cherenkov detector currently under construction in the Mediterranean Sea. It is also designed to serve as a platform for investigations of the deep-sea environment. In this context, the ANTARES group at the University of Erlangen will integrate acoustic sensors within the infrastructure of the experiment. With this dedicated setup, tests of acoustic particle detection methods and deep-sea acoustic background studies shall be performed. The aim of this project is to evaluate the feasibility of a future acoustic neutrino telescope in the deep sea operating in the ultra-high energy regime. In these proceedings, the implementation of the project is described in the context of the premises and challenges set by the physics of acoustic particle detection and the integration into an existing infrastructure. 1. Introduction Towards the detection of neutrinos with energies exceeding 100 PeV, the use of acoustic pressure waves produced in neutrino-induced cascades is a promising approach. One advantage of acoustic waves is the absorption length of the order of 1 km for the peak spectral density of the generated sound waves around 20 kHz [2]. To investigate the feasibility of building a detector in the deep sea based on this method, it is necessary to understand the acoustic background conditions and characteristics of transient noise sources in detail on a long time scale. Especially the rate and correlation length of neutrino-like acoustic background events is not known and yet is a prerequisite for the estimation of the sensitivity of such a detector. The aim of the project described here is to measure the acoustic conditions of the deep-sea environment at the ANTARES site with a dedicated array of custom-designed acoustic sensors at different distances. Towards this goal several additional basic detector elements (storeys, cf. Sec. 2) of the ANTARES neutrino telescope will be equipped with acoustic sensors. On these storeys the sensors will substitute the optical sensors (photo-multiplier tubes, PMTs) used for Cherenkov detection of neutrinos. Several components of the ANTARES infrastructure have to be modified or substituted to integrate the acoustic sensors into the ANTARES data acquisition (DAQ) scheme. In these proceedings the changes will be described, and an overview of the project will be given (cf. also [3]).