ARENA Workshop, May, 2005 First Activities in Acoustic Detection of Particles in UPV M. Ardid, J. Ramis, V. Espinosa, J.A. Martínez-Mora, F. Camarena, J. Alba, V. Sanchez-Morcillo Departament de Física Aplicada, E.P.S. Gandia, Universitat Politècnica de València

ARENA Workshop, May, 2005 Contents DISAO group –Experience in acoustic fields and connections with neutrino detection First activities related to particle detection –Design of piezoelectric transducers –Characterization and calibration of hydrophones –Simulation of the propagation of the signal in the sea Conclusions and future

ARENA Workshop, May, 2005 ULTRASOUNDS TRANSDUCTION Non-destructive analysis (fruits, leakages) Materials Positioning Vibroacoustics, holography Biomass in fisheries Piezoelectrics Neutrino detection Difussors, room acoustics Thermoacoustic Model Quality of sound Intense beamsNoise mapping NON-LINEAR ACOUSTICS PSYCHOACOUSTICS DISAO group 14 researchers working in: (3 of them with Ph.D. in experimental particle physics)

ARENA Workshop, May, 2005 DISAO group Non-destructive analysis Positioning Thermoacoustic model NEUTRINO DETECTION Intense beams Noise mapping Quality of sound Room acoustics Diffusors Vibroacoustics Materials Piezoelectrics 14 researchers working in: Biomass in fisheries ULTRASOUNDS TRANSDUCTION NON-LINEAR ACOUSTICS PSYCHOACOUSTICS Holography

ARENA Workshop, May, 2005 Connections with neutrino detection Transducers of ultrasounds Example of application: Non-destructive analysis of fruits

ARENA Workshop, May, 2005 Connections with neutrino detection Studies in the sea Example of application: study of biomass in fisheries Echoes of fishes Surface reference transducer Emission reference Surface echo Time (ms)

ARENA Workshop, May, 2005 Connections with neutrino detection Non-linear acoustics Self-organization of sound E()E() Intense beamsThermoacoustic resonator Amplitude Spectrum Initial conditions Self-trapped states of sound

ARENA Workshop, May, 2005 First activities related to neutrino detection

ARENA Workshop, May, 2005 Design of piezoelectrics transducers Software based on the localized constants method using the modified KLM model, R. Krimholtz et al., Electronic Letters 6 (1970) Electric gate V 1 I 1 Backwards acoustic gate F 2 u 2 Forward acoustic gate F 2 u 2 R0R0 jX 1 C0C0 Z 0 0 /4  m 1 : 

ARENA Workshop, May, 2005 Design of piezoelectrics transducers Simulation of the whole transducer (not only the piezoelectric) Friendly interface

ARENA Workshop, May, 2005 Design of piezoelectrics transducers Results Input acoustic impedance Emitting and Receiving Transfer Functions Excitation Response in Time and Frequency

ARENA Workshop, May, 2005 Design of piezoelectrics transducers Next steps: –Exhaustive comparison between simulation and experimental results –Comparison of the results with finite element methods –Include piezoelectrics with different geometries (not only discs/cylinders) –Upgrade the model including more effects by using secondary circuits –Use it, to design the best piezoelectrics sensors for acoustic detection of neutrinos Future: –Include the improved model in the simulation package for acoustic detection of neutrinos

ARENA Workshop, May, 2005 Characterization and calibration of hydrophones expected Rough calibration The calibration of hydrophones in the lab is not an easy task: –There are reflections, diffraction, etc, which could affect well-known methods of calibration like the reciprocity method. –We are working in designing a method for hydrophone calibration

ARENA Workshop, May, 2005 Characterization and calibration of hydrophones MLS (Maximum Length Sequence) signal: –Pseudo-random signal, analogical version of digital sequence consisting of values 1 and -1. –Periodic with the period T=2 N - 1, where N is the "order of the sequence", and has a flat frequency distribution. –Circular autocorrelation provides a delta function MLS order 6

ARENA Workshop, May, 2005 Characterization and calibration of hydrophones Time and frequency response of the system (two hydrophones + tank) using the MLS signal –knowing the response of two elements, we could know the third one

ARENA Workshop, May, 2005 Characterization and calibration of hydrophones Next steps: –Learn more about the different effects involved in acoustic calibration of hydrophones –Study the calibration with different signals (short signals with few pulses, white noise, continuous waves, sweep signal, MLS) –Improve the conditions of measurement and calibration of the lab: building an anechoic tank –Design a trustful system of calibration in the lab –Look for a ‘good and simple’ “neutrino” signal for calibration Future: –Design and characterize different sensors for neutrino detection –Design a trustful system of calibration in neutrino detection sites

ARENA Workshop, May, 2005 Simulation of the propagation of the signal in the sea Since recently we are using The Acoustic ToolBox, which includes four acoustic models: –BELLHOP: A beam/ray trace code –KRAKEN: A normal mode code –SCOOTER: A finite element FFP code –SPARC: A time domain FFP code We show the application of this code to learn about the contribution of the sea surface noise to the deep-water noise in the Mediterranean Sea.

ARENA Workshop, May, 2005 Simulation of the propagation of the signal in the sea BELLHOP: beam/ray tracing. The rays with small angles of emission are curved and do not reach the deep sea.  =2º  =6.7º  =11.4º  =16º 

ARENA Workshop, May, 2005 Simulation of the propagation of the signal in the sea Transmission loss for the propagation of sound in the Mediterranean Sea for a source in the surface and measuring in the sea floor for different depths given by the normal mode code KRAKEN. Depth of the sea (m) f = 1 kHz f = 15 kHz, no absorp. in water Depth of the sea (m)

ARENA Workshop, May, 2005 Simulation of the propagation of the signal in the sea Next steps: –Learn more about acoustical oceanography codes –Include some effects, which are not taken yet into consideration –Use the parameters of possible neutrino detector sites (if available) –Compare the results with other simulation packages and validate them –Upgrade the model for acoustic neutrino detection purposes. Future: –Include the improved model in the simulation package for acoustic detection of neutrinos –Use it for the inverse problem, neutrino source location

ARENA Workshop, May, 2005 Conclusions and Future Conclusions: –We have started to work in some aspects of acoustic neutrino detection: design of piezoelectric transducers, calibration of hydrophones and propagation of acoustic signal in the sea, reaching some results but knowing that there is a long way still. –We have seen that we can apply knowledge from different acoustic fields to the neutrino detection problem –Therefore, multidisciplinary collaboration of acoustic and particle physics people is encouraged Future: –To consolidate this line of research in our group –To participate in an international collaboration which faces this complex problem in an organised and efficient way.