Studies of a full-scale mechanical prototype line for the ANTARES neutrino telescope and tests of a prototype instrument for deep-sea acoustic measurements

A full scale mechanical prototype line was deployed to a depth of 2500 m to test the leak tightness of the electronics 4 containers and the pressure-resistant properties of an electromechanical cable under evaluation for use in the ANTARES 5 deep-sea neutrino telescope. During a month-long immersion study, line parameter data were taken using miniature 6 autonomous data loggers and shore-based optical time domain reflectometry. Details of the mechanical prototype line, the 7 electromechanical cable and data acquisition are presented. Data taken during the immersion study revealed deficiencies in 8 the pressure resistance of the electromechanical cable terminations at the entry points to the electronics containers. The 9 improvements to the termination, which have been integrated into subsequent detection lines, are discussed. The line also 10 allowed deep sea acoustic measurements with a prototype hydrophone system. The technical setup of this system is described,and the first results of the data analysis are presented.