Development of a compact acoustic calibrator for ultra-high energy neutrino detection

1. Development of a compact acoustic calibrator for ultra-high energy neutrino detection S . Adrián, M. Ardid, M. Bou-Cabo, G. Larosa, C.D. Llorens, J.A. Martínez-Mora IGIC- UniversitatPolitècnica de València, Spain

2. Index • Introduction • Acoustic Detection • Parametric Acoustic Sources • Parametric acoustic sources • Previous work • Planar Transducers • Cylindrical Transducers • Studies for long distances • Experimental measurements in a pool. • Array • Extrapolation at km range • Prototype for a future sea campaign • Array design • Mechanical structure. • Electronics • Conclusions • Future steps Development of a compact acoustic calibrator for ultra-high energy neutrino detection

3.  Hadronic Cascade ≈1km Introduction: Neutrino’sacousticsignal When a UHE neutrino interacts whit a nuclei in water… Temperature Time h ∆t G.A.Askaryan. Hydrodynamicalemission of tracks of ionisingparticles in stableliquids.J. At. Energy 3 (1957) 921. Bipolar Pulse CylindricalPropagationPancakeDirectivity ≈ 1º CALIBRATOR:ParametricAcousticSources Development of a compact acoustic calibrator for ultra-high energy neutrino detection

4. Introduction: ParametricAcousticSources • Parametric acoustic generation is a well known non linear effect first time studied at 60's. • Parametric acoustic generation consist in a non linear effect that occurs along the sound wave path when a transducer is fed with a modulated signal with two close frequencies. • Small fraction of energy is converted into new spectral components. • Larger frequencies are rapidly absorbed in the medium → most interesting harmonic is the frequency difference. • It can be used to obtain a low frequency secondary signal with directivity similar to the high frequency primary beam. Development of a compact acoustic calibrator for ultra-high energy neutrino detection

5. Introduction: ParametricAcousticSources • Modulation of signal for emission calculated from parametric theory: • First studies were done using planar transduces in order to understand and control the parametric acoustic generation. M.Ardid et al. “Use of parametric acoustic sources to generate neutrino-like signals,” Nucl. Instr. and Meth. A, vol. 604, Jun. 2009, pp. S208-S211. • To disentangle the primary and secondary beams we applied different filters. Recorded signal and bipolar pulse Development of a compact acoustic calibrator for ultra-high energy neutrino detection

6. 3.PreviousWork (cylindricaltransducers) • Emitterhydrophone:10 kHz Free Flooded Ring • 380 kHz frequency resonance used for our studies • It is usually used at lower frequencies, so it can be used as well as a classical transmitter at high frequency Receiver hydrophone: More sensitive below 100 kHz than for 380 kHz. More sensitive to the bipolar pulse (hardware filtering) Z axis X axis Y axis • Emitter is fixed, whereas the receiver hydrophone scans along X, Y and Z axis using a micropositioning system. • ArbitrarysignalgeneratorPCI-5412 (National Instruments). • RF amplifier ENI 1040L (400W, +55dB, Rochester, NY). • DigitizerPCI-5102 (National Instruments) • Dimension of tank is  1 m3 1.10 x 0.85 x 0.80 m3 Development of a compact acoustic calibrator for ultra-high energy neutrino detection

7. 3.PreviousWork (cylindricaltransducers) • Directivitystudies • Shapestudies: Control generation of bipolar pulse Emitted signals with different width (different sigma used) Emitted signals with different adding time between the increasing and decreasing amplitude regions Development of a compact acoustic calibrator for ultra-high energy neutrino detection

8. 3.PreviousWork (cylindricaltransducers) Relationshipbetweentheamplitude of theprimary and thesecondarybeam: M.Ardid et al. “R&D studies for the development of a compact transmitter able to mimic the acoustic signature of a UHE neutrino interaction,” Nucl. Instr. and Meth. A, doi:10.1016/j.nima.2010.11.139. Development of a compact acoustic calibrator for ultra-high energy neutrino detection

9. 4.Studies in a pool • Measurements in a pool. Single element. Pool dimensions: 6.3 x 3.6 x 1.5 m3 Development of a compact acoustic calibrator for ultra-high energy neutrino detection

10. 4.Studies in a pool • Measurements in a pool. Array system FWHM ≈ 7 º FIRST PROTOTYPE Pool dimensions: 6.3 x 3.6 x 1.5 m3 Development of a compact acoustic calibrator for ultra-high energy neutrino detection

11. 4.Studies for long distances • Extrapolation Received Signal V(t) FFT Spectral Components VPSD(f) IFFT S(f) [V/pa] Received Signal P (t) Spectral Components APSD(f) α(f) Propagation IFFT Temporal reconstruction. Propagated signal P (t) Development of a compact acoustic calibrator for ultra-high energy neutrino detection

12. 4.Studiesforlongdistances • Extrapolation with single element working Digital filtering 1 element  0.035 Pa 3 elements  0.105 Pa Reference of pressure 0.1 Pa at 1 km by neutrino of interaction Propagation effect Development of a compact acoustic calibrator for ultra-high energy neutrino detection

13. 5.Prototype for future sea campaign • Array design 26,5 cm 17,5 cm SECOND PROTOTYPE 36,4 cm Flexible Polyurethane EL110H • Water resistance • Electrical insulation • High frequency and high voltage applications • Resistance to thermal and mechanical shock • No significant changes in the mechanical response of the transducer Two possible operation modes: 380 kHz  parametric generation [ 5-50 ] kHz  calibration, positioning… Development of a compact acoustic calibrator for ultra-high energy neutrino detection

14. 5.Prototype for future sea campaign Rotation control Fixing bar • Mechanical structure. Rotating arm Array Fixation • Secure the device to the boat. • Dipping it. • Control of the rotation angle. Extensible 20 m Development of a compact acoustic calibrator for ultra-high energy neutrino detection

15. 5.Prototype for future sea campaing • Pulse Width Modulation • Class D Amplification • Simplicity of design • No large heat sinks  less weight and volume of the electronics system. • Power amplifier has a minimum power at idle state • Electronics This technique has been implemented in the electronics of the acoustic transceivers for positioning systems in underwater neutrino telescope. Development of a compact acoustic calibrator for ultra-high energy neutrino detection

16. 6.Conclusions • We have presented the results obtained in relation with: • The studies of the parametric acoustic sources. • The prototype of the array system. • The results for the simulations. The solution proposed based in parametric acoustic sources could be considered as good candidate to generate the acoustic neutrino-like signals, achieving the reproduction of both specific characteristics the signal predicted by theory: • bipolar shape in time • pancake directivity • Taking into account the work range of the transducers and the adaptation of the electronics to both applications it is possible, with the same device, to carry out several tasks: • Acoustic detection calibration. • Acoustic sensor calibration. • Positioning. Development of a compact acoustic calibrator for ultra-high energy neutrino detection

17. 6.Futuresteps • Deployment and testing of the electronic board. • This will improve the efficiency of the parametric effect • This will allow experimental measurements at long distance. • Complete the characterization of the prototype: • Laboratory • Gandia´sharbour • Test the behavior of the transmitter using the Amadeus system. • Future sea campaign (vessel) • In situ integration at neutrino telescope Development of a compact acoustic calibrator for ultra-high energy neutrino detection

18. Thank you

19. Development of a compact acoustic calibrator for ultra-high energy neutrino detection