1. A Device for Detection of Acoustic Signals from Super High Energy Neutrinos Presenter: Presenter: G.L.Pan'kov Applied Physics Institute of Irkutsk State University Irkutsk, Russia 2005

2. 2 Baikal Collaboration Institute of Nuclear Research, Russian Academy of Sciences (Moscow, Russia) : V.M.Aynutdinov, V.A.Balkanov, L.B.Bezrukov,D.A.Borschev, I.A.Danilchenko, Ya.I. Davidov, Zh.-A.M.Djilkibaev, G.V.Domogatsky, O.N.Gaponenko, A.M.Klabukov, S.I.Klimushin, A.P.Koshechkin, B.K.Lubsandorzhiev, S.P.Mikheyev, A.I.Panfilov, D.P.Petuhov, P.G.Pokhil, V.A,Poleschuk, B.A. Shaibonov, E.A.Vyatchin, V.A.Zhukov Irkutsk State University (Irkutsk, Russia): N.M.Budnev, A.G.Chensky, O.A.Gress, T.I.Gress,O.G.Grishin, A.N.Dyachok, R.R.Mirgazov, Yu.V.Parfenov, A.A.Pavlov, A.A.Kochanov, G.L.Pan'kov, L.V.Pan'kov, V.Yu.Rubtzov, Yu.A.Semenei,B.A.Tarashansky Moscow State University (Moscow, Russia): L.A.Kuzmichev, M. Mehanov, E.A.Osipova, E.G.Popova, V.V.Prosin, A. Shirokov, I.V.Yashin Nizhni Novgorod State Technical University (Nizhni Novgorod, Russia): V.F.Kulepov, M.B. Milenin, S.V. Fialkovski St.Petersburg State Marine Technical University (St.Petersburg, Russia): M.I.Rozanov Kurchatov Institute (Moscow, Russia): A.I.Klimov Joint Institute for Nuclear Research (Dubna, Russia): I.A.Belolaptikov, K.V.Konischev,E.N.Pliskovsky, R.V.Vasiljev DESY -Zheuthen (Zeuthen, Germany): T.Mikolajski,Ch.Spiering, R.Wischnewski

3. 3  The main requirements 3 dimensional net of 4 hydrophones as minimum 3 dimensional net of 4 hydrophones as minimum Sampling frequency of ADC not less then 100 kHz Sampling frequency of ADC not less then 100 kHz  The additional requirements The preliminary analysis under water to reject background The preliminary analysis under water to reject background Operation mode with external Trigger : from Baikal Neutrino Telescope NT200+ Operation mode with external Trigger : from Baikal Neutrino Telescope NT200+

4. 4 A Device for Detection of Acoustic Signals

5. 5 Minicomputer ADC card Modem Hph3 Hph1 Hph2 Hph4 Power supply Signal The schema of the device BOX Power

6. 6 Shore Connection: via NT200+ Acoustic DAQ AVIV Modem Flex DSL Modem AVIV Modem Electric shore cable Master signal From NT-200+ 2Mbit/s 512 kbit/s Acoustic Device NT200+ Central DAQ

7. 7 Antenna of the Device

8. 8 Electronics

9. 9 The devices tasks  Continues monitoring of statistical acoustic noise parameters. (Mean value, dispersion and so on).  The search of signals of definite waveform and length.  The collection of continues data after receiving of master signal from NT-200+. (The most important regime).

10. 10 Autonomous operating mode Acoustic Time Series From Hydrophones Extraction of Statistical Information Signal Detection And Classification Store Signals in a Dynamic Arrays Check signals for “Time Window” condition Direction and Distance Estimation Final Data Representation Send Data to the Shore Station

11. 11 Statistical characteristics of a signal Mean Value (Signal Level): Noise level estimation: Processing of an array with elements : 1)2) 3) Internal Dispersion (for control of electronics) External Dispersion Total Dispersion

12. 12 We accept only signals which satisfy to the following condition: - time of propagation of a signal from one hydrophone to another - distance between two hydrophones - sound velocity at the depth where antenna placed - error in estimation of “Time window” condition

13. 13 Accepted and Rejected signals

14. 14 Parameters of waveform for classification procedure  The number of quasiperiods  Maximum and minimum amplitude of each extremum of signal  The total length of signal  The length of each component of signal

15. 15 Signal Detection and Classification Procedure Statistical Module Signal Detection Module Dynamic Array

16. 16 Direction and Distance Estimation  For signals from the distances >50m acoustic front is flat.  We measure time coordinates of each signal:  The procedure of obtaining consists in minimization of a functional: where where Start point of a signal in time series Start point of a signal in time series Position of center of a pyramid in the chosen system of coordinates Position of center of a pyramid in the chosen system of coordinates Positions of hydrophones Positions of hydrophones The moment of passage sound front through a point The moment of passage sound front through a point Time estimation mistake Time estimation mistake

17. 17 07-04-2005 The bipolar impulse

18. 18 07-04-2005 Unknown impulse

19. 19 Electric Pickup =200us

20. 20 An example of bipolar impulse = 60us

21. 21 Mean STD in all channels 06-04-2005 19:04 --- 07-04-2005 00:30 One measurement per minute

22. 22 Mean STD in all channels 07-04-2005 22:29 --- 08-04-2005 08:27 One measurement per minute

23. 23 Zenith angel distortion 07-04-2005 20 degrees Absorption hat Hydrophone

24. 24 Acoustic device

25. 25 The Summary 1. A device for registration and preliminary analysis of acoustic signals has been constructed and tested in-situ in April, 2005. 2. In 2006, we intend to deploy the device for one year operation together with the Baikal Neutrino Telescope. Possible location: ~100m below water surface.