title: Transducer Development and Characterization for Underwater Acoustic Neutrino Detection Calibration.
abstract: A short bipolar pressure pulse with "pancake" directivity is produced and propagated when an Ultra-High Energy (UHE) neutrino interacts with a nucleus in water. Nowadays, acoustic sensor networks are being deployed in deep seas to detect this phenomenon as a first step toward building a neutrino telescope. In order to study the feasibility of the method, it is critical to have a calibrator that is able to mimic the neutrino signature. In previous works the possibility of using the acoustic parametric technique for this aim was proven. In this study, the array is operated at a high frequency and, by means of the parametric effect, the emission of the low-frequency acoustic bipolar pulse is generated mimicking the UHE neutrino acoustic pulse. To this end, the development of the transducer to be used in the parametric array is described in all its phases. The transducer design process, the characterization tests for the bare piezoelectric ceramic, and the addition of backing and matching layers are presented. The efficiencies and directivity patterns obtained for both primary and parametric beams confirm that the design of the proposed calibrator meets all the requirements for the emitter.
authors.affiliation: Institut d'Investigació per a la Gestió Integrada de les Zones Costaneres (IGIC), Universitat Politècnica de València (UPV), 46730 Gandia, Spain. masalcos@upv.es.
authors.forename: María
authors.initials: M
authors.lastname: Saldaña
authors.affiliation: Institut d'Investigació per a la Gestió Integrada de les Zones Costaneres (IGIC), Universitat Politècnica de València (UPV), 46730 Gandia, Spain. cdavid@upv.es.
authors.forename: Carlos D
authors.initials: CD
authors.lastname: Llorens
authors.affiliation: Institut d'Investigació per a la Gestió Integrada de les Zones Costaneres (IGIC), Universitat Politècnica de València (UPV), 46730 Gandia, Spain. ivfeen@upv.es.
authors.forename: Ivan
authors.initials: I
authors.lastname: Felis
authors.affiliation: Institut d'Investigació per a la Gestió Integrada de les Zones Costaneres (IGIC), Universitat Politècnica de València (UPV), 46730 Gandia, Spain. jmmora@fis.upv.es.
authors.forename: Juan Antonio
authors.initials: JA
authors.lastname: Martínez-Mora
authors.affiliation: Institut d'Investigació per a la Gestió Integrada de les Zones Costaneres (IGIC), Universitat Politècnica de València (UPV), 46730 Gandia, Spain. mardid@fis.upv.es.
authors.forename: Miguel
authors.initials: M
authors.lastname: Ardid
keywords: Ultra-High Energy neutrinos; acoustic calibrator; acoustic detection; parametric technique; piezo-ceramic tube transducers; underwater neutrino telescopes