KM3Net neutrino telescope in the mediterranean
Deep dive into the neutrino telescope: a neutrino is an elementary particle that interacts only via the weak subatomic force and gravity.
The mass of the neutrino is much smaller than any other known elementary particles. Neutrino Telescope are very large installations that has the scope of detect a statistical relevant number of neutrinos are often built underground or in deep water to isolate the detector form cosmic rays and other background installation.
Various detection methods have been used but the field of neutrino astronomy is still very much in its infancy. The latest research are about acoustic detection via thermoacoustic effect.
Dedicated studies are done by Antares, IceCube and KM3NeT scientist of KM3Net have formed a Collaboration to build and operate the first phase of the infrastructure in the Mediterranean Sea.
From May 2019 the detector is running with two detection units recently installed.
For the deployment, the units are lowered at 2.5km from the deployment vessel to the sea floor.
Using and acoustic system based on a set of transponders anchored on the sea floor.
The selected hydrophone for this project is the DG1330
The DG1330 is a digital omnidirectional hydrophone, a professional tool specifically designed and produced for the KM3Net Neutrino project, where our hydrophone was selected by INFN to record acoustic signals at depths of up to 3500 m. The sensor consists of a spherical piezo-ceramic element, read-out by an analogue board splitting the signal in two lines with different gains (+46 dB and +26 dB respectively). Two streams are sampled by a stereo 24 bit commercial ADC (CS-4270) and converted into AES protocol using a DIT (Digital Interface Transmitter).
Two hydrophone productions are available, without and with an analogue signal high-pass filtering stage. The filter frequency is 700 Hz, to reject the low frequency ambient sea-noise (which follows a 1/f shape, and flattens at about 5 kHz) The not-filtered version can be also used for acoustic noise monitoring and marine bioacoustics.