First Activities in Acoustic Detection of Particles in UPV

ARENA Workshop, 17-19 May, 2005

First Activities in Acoustic Detection of

Particles in UPVM. Ardid, J. Ramis, V. Espinosa, J.A. Martínez-Mora,

F. Camarena, J. Alba, V. Sanchez-MorcilloDepartament de Física Aplicada, E.P.S. Gandia, Universitat Politècnica de València


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


ULTRASOUNDS TRANSDUCTIONNon-destructive analysis (fruits, leakages) MaterialsPositioning Vibroacoustics, holographyBiomass in fisheries PiezoelectricsNeutrino detection Difussors, room acousticsThermoacoustic Model Quality of soundIntense beams Noise mapping

NON-LINEAR ACOUSTICS PSYCHOACOUSTICS

DISAO group14 researchers working in: (3 of them with Ph.D. in experimental particle physics)


DISAO group

Non-destructive analysis

Positioning

Thermoacoustic modelNEUTRINO DETECTION

Intense beams

Noise mapping

Quality of sound

Room acoustics

DiffusorsVibroacoustics

Materials

Piezoelectrics

14 researchers working in:

Biomass in fisheries

ULTRASOUNDS

TRANSDUCTION

NON-LINEAR ACOUSTICS

PSYCHOACOUSTICS

Holography


Connections with neutrino detection

• Transducers of ultrasoundsExample of application: Non-destructive analysis of fruits

200

220

240

260

280

300

320

340

360

380

400

1,5 3,5 5,5 7,5 9,5

F (N)

V (m

V)

Serie1

Serie2

Serie3

Serie4

Serie5



• Studies in the seaExample of application: study of biomass in fisheries

Echoes of fishes

Surface reference transducerEmission reference

Surface echoTime (ms)20 12 14 164



• Non-linear acoustics

Self-organization of sound

22

2

pTTt

T

Tpipiapt

p

E()Intense beams Thermoacoustic resonator

Amplitude

Spectrum

Initial conditions

V

VBVGz

V 22

41

Self-trapped states of sound


First activities related to neutrino detection


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 gateV1 I1

Backwards acoustic gate

F2 u2

Forward acoustic gate

F2 u2

R0

jX1C0

Z0 0/4 m Z0 0/4 m

1 :



• Simulation of the whole transducer (not only the piezoelectric)

Friendly interface



• Results

-3 -2 -1 0 1 2 3

x 10-5

-8

-6

-4

-2

0

2

4

6

8x 10

-6 Respuesta a la excitac ión Eg(t)

Tiempo (t)

Eg(

t)

2.5 3 3.5 4 4.5 5 5.5 6

x 105

-1

-0.5

0

0.5

1Respuesta a la excitac ión Eg(f)

Frecuencia (f)E

g(f)

Input acoustic impedance

Emitting and Receiving Transfer Functions

Excitation Response in Time and Frequency



• 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


Characterization and calibration of hydrophones

0 2 4 6 8 10 12

x 104

-10

0

10

20

30

40

frequency (Hz)

inte

ns

ity

(d

B)

Rough calibration of a hydrophone

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



• MLS (Maximum Length Sequence) signal:– Pseudo-random signal, analogical version of digital sequence

consisting of values 1 and -1. – Periodic with the period T=2N - 1, where N is the "order of the

sequence", and has a flat frequency distribution.

– Circular autocorrelation provides a delta function MLS order 6



0 2 4 6 8 10 12

x 104

-130

-120

-110

-100

-90

-80

-70

frequency (Hz)

Inte

ns

ity

dB

(a

. u

.)

Frequency response

0 2000 4000 6000 8000 10000 12000-0.2

0

0.2

0.4

0.6

0.8

1

1.2

time (samples fs=250 kHz)

Inte

nsi

ty (

a.u

.)

Time Response (after deconvolution)

• 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



• 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


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.



• BELLHOP: beam/ray tracing. The rays with small angles of emission are curved and do not reach the deep sea.

0 5 10 15 20 25 30 35 40

0

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

Range (km)

Dep

th (

m)

Ray tracing in the Mediterranean Sea

=2º

=6.7º

=11.4º

=16º


0 1 2 3 4

x 104

60

80

100

120

140

160

180

200

Range (m)

Tra

ns

mis

sio

n L

os

s (

dB

)

Transmission Loss in deep Mediterranean 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.

0 10 20 30 40

60

70

80

90

100

110

120

130

Range (km)

Tra

nsm

issi

on L

oss

(dB

)

Transmission Loss in deep Mediterranean Sea

Depth of the sea (m)

2400

3400

4100

f = 1 kHz f = 15 kHz, no absorp. in water

Depth of the sea (m)

2400

4100



• 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


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.

Documents

First Activities in Acoustic Detection of Particles in UPV