Preliminary results on hydrophones calibration with proton beam

Huge sensitive volumes will be required to identify interactions of U.H.E. cosmic neutrinos with energy above 10(16) eV. New detectors and new techniques have to be developed to open this future field of H.E. astrophysics. We report on the study of acoustic signals induced by the interaction in water of a high intensity low energy proton beam (ITEP, Moscow). Acoustic signals have been collected by means of high sensitivity deep-sea hydrophones, for proton energy deposition close to 0.1 Joule. Hydrophones sensitivity has been previously characterized at the acoustic test facilities of IDAC-CNR (Rome). Results show a good linearity between the proton beam intensity and the hydrophones signal amplitude. Results are encouraging for the future detection of high-energy neutrino-induced showers developing in deep-sea water.