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ANTARES: Towards Acoustic Detection of Highest Energy Neutrinos

ANTARES: Towards Acoustic Detection of Highest Energy Neutrinos. Kay Graf for the ANTARES Collaboration Erlangen Centre for Astroparticle Physics VLV n T 09, Athens, Oct. 13 th – 15 th 2009. Outline. Motivation The AMADEUS System Positioning Source Reconstruction. Motivation.

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ANTARES: Towards Acoustic Detection of Highest Energy Neutrinos

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  1. ANTARES: Towards Acoustic Detection of Highest Energy Neutrinos Kay Graf for the ANTARES Collaboration Erlangen Centre for Astroparticle Physics VLVnT 09, Athens, Oct. 13th – 15th 2009

  2. Outline • Motivation • The AMADEUS System • Positioning • Source Reconstruction Kay Graf (ECAP) – VLVnT 09, Athens – October 2009

  3. Motivation Kay Graf (ECAP) – VLVnT 09, Athens – October 2009

  4. Ultra-high Energy Neutrino Astrophysics at energies above 1014-15eV: • universe becomes opaque to photons at Mpc range • CR protons, nuclei are galactic up to ~1018eV, suffer GZK cut-off above that • neutrinos unabsorbed at all energies → sources exist to at least 3x1020eV • UHE neutrinos are the only viable messenger beyond the local universe n viable throughout these regions P. Gorham Kay Graf (ECAP) – VLVnT 09, Athens – October 2009

  5. Highest Energy Neutrinos water/ice Cherenkov telescopes complementary techniques 10-4 • astrophysics: origin of UHECR GZK neutrinos • cosmology: top-down scenarios topological defects • particle physics: neutrino cross section TD 10-6 Flux × E2 [eV m-2 s-1 sr-1] 10-8 10-10 14 16 18 20 22 24 log10(E[eV]) T. Karg, arXiv:astro-ph/0608312 • for GZK n: >100km2 ∙ 2p ∙ year detector needed Kay Graf (ECAP) – VLVnT 09, Athens – October 2009

  6. neutrino (U)HE  Detection Methods • balloon • satellite • telescope  cascade m sonic wave  cascade opticalCherenkov radio Cherenkov  PMT array antenna array hydrophone array Optical Cherenkov water, ice latt < 100m Radio Cherenkov ice, salt, rock latt ~ 1km (ice) Acoustic Detection water, ice, salt latt > 1km (water) + hybrid detectors Kay Graf (ECAP) – VLVnT 09, Athens – October 2009

  7. Acoustic Signal Properties shower maximum Ecasc= 1 EeV @ 1km peak pressure (mPa/EeV) distance along shower axis (m) log10 (radial distance (m)) log10 (radial distance (m)) Acorne Coll. astro-ph/0704.1025 T. Karg, astro-ph/0608312v1 bipolar signal (~10kHz) with disk-like geometry Kay Graf (ECAP) – VLVnT 09, Athens – October 2009

  8. Simulations of an Acoustic Detector 200 acoustic antennas/km3 • strong dependence: Veff(Pthres) • Pthres mainly given by ambient noise • a threshold of 5mPa seems reachable in the deep-sea Pthres T. Karg, arXiv:astro-ph/0608312 Kay Graf (ECAP) – VLVnT 09, Athens – October 2009

  9. The AMADEUS System Kay Graf (ECAP) – VLVnT 09, Athens – October 2009

  10. The AMADEUS Project Feasibility Study • detector environment (hybrid) • detector calibration functionality • sensor design and positioning • background studies • signal processing techniques integration of acoustic setup into the ANTARES neutrino telescope Kay Graf (ECAP) – VLVnT 09, Athens – October 2009

  11. F ANTARESsite The ANTARES Neutrino Telescope • optical Cherenkov Telescope • 875 PMT • at 2500m water depth • Vinst~ 200 x 200 x 400 m3 Kay Graf (ECAP) – VLVnT 09, Athens – October 2009

  12. The AMADEUS System • taking data since 5-Dec-2007 • completely installed since 30-May-2008 • acoustics on L12: data from 6-Sep to 24-Dec 2008 “pingers“ (acoustic RxTx) on each anchor Kay Graf (ECAP) – VLVnT 09, Athens – October 2009

  13. AMADEUS Facts • characteristics • 36 sensors at 6 storeys (1 – 350m distance, 34 active) • 16bit @ 250kSps sampling • ~ -125dB re 1V/mPa sensitivity • ~85-90% uptime • data acquisition • all data to shore • raw: 20 MByte/s (1.5 TByte/d) • filtered: 0.3 MByte/s (4 GByte/d), up to now: 4 TByte • excellent stability of all DAQ parts Kay Graf (ECAP) – VLVnT 09, Athens – October 2009

  14. noise and transient additional tails ~60dB S/N (SINAD), no significant crosstalk Data Samples: Amplitude Histograms noise at different sensors • gaussian profile • linear correlation between sensors (factor ~ 99%) Samples (per ADC count) Samples (per ADC count) Kay Graf (ECAP) – VLVnT 09, Athens – October 2009

  15. Positioning Kay Graf (ECAP) – VLVnT 09, Athens – October 2009

  16. Positioning: Method for Reconstruction use emissions from the ANTARES acoustic positioning system (not directly connected with AMADEUS) • → positioning of individual sensors: • use absolute time from > 3 pingers:| rreception – remission | = cs¢(treception – temission – toffset) • treception by threshold crossing of signal envelope • temission from positioning system • → position/orientation by fitting storey geometry Kay Graf (ECAP) – VLVnT 09, Athens – October 2009

  17. Positioning: Example • 5 days of data • completely independent derivation of heading Kay Graf (ECAP) – VLVnT 09, Athens – October 2009

  18. Acoustic Modules (AMs)‏ Piezo sensors + preamplifiers design allows for integration of acoustic sensors into pressure housing of photo sensors  no need for additional mechanical structures Kay Graf (ECAP) – VLVnT 09, Athens – October 2009

  19. Pinger Signals for Reconstruction of Hydrophones and AMs AMs Hydros signal quality of AMs slightly degraded w.r.t. hydrophones(coupling, ringing of sphere, ...) Kay Graf (ECAP) – VLVnT 09, Athens – October 2009

  20. Positioning with AMs 4 5 1 0 2 3 • calculate difference of individually reconstructed sensor position • some issues/systematics need to be investigated Kay Graf (ECAP) – VLVnT 09, Athens – October 2009

  21. Heading on AM Storey Sensors 0 and 2 • systematic effects due to orientation of sensors w.r.t. pingers need to be investigated • for two sensors with distance at 250mm (in a sphere) better than 10° resolution reachable Kay Graf (ECAP) – VLVnT 09, Athens – October 2009

  22. Positioning Option for KM3NeT • AMADEUS-like acoustic sensors have the potential to combine: • positioning • investigation of acoustic neutrino detection techniques • marine science • Acoustic Modules (AMs) allow for an integration of acoustic sensors into Opto-Acoustical Modules (OAMs). • First Measurements in the Lab: • no significant degradation of performance of acoustic sensors by ANTARES HV base • noise expected mainly from DC-DC converter Kay Graf (ECAP) – VLVnT 09, Athens – October 2009

  23. Source Reconstruction Kay Graf (ECAP) – VLVnT 09, Athens – October 2009

  24. Source Direction Reconstruction: A Dolphin most probable source direction 1 0 -1 90 0 -90 • beam forming or time difference algorithms used • uncertainty <1° (mainly due to binning in the algorithm) Intensity (au)  (°) Amplitude (au) -180 0 180 0 0.5 1 f (°) time (ms) Kay Graf (ECAP) – VLVnT 09, Athens – October 2009

  25. Angular Distribution of Marine Sound Sources • direction reconstruction for one storey • all types of transient signals included • origin points horizontal to north • one month of data Kay Graf (ECAP) – VLVnT 09, Athens – October 2009

  26. Tracking of a Source • reconstruction with one storey • all triggered events within 500s displayed Kay Graf (ECAP) – VLVnT 09, Athens – October 2009

  27. Summary • at UHE neutrinos are the only viable messenger beyond the local universe • need a >100km2 ∙ 2p ∙ year detector • acoustic detection promising candidate • complementary to optical and radio techniques (hybrid detection) • AMADEUS in ANTARES: feasibility study for a future acoustic detector • dedicated array in a detector environment – hybrid detection possible • successfully operated since 12/2007 • return of experience for future arrays (opto-acoustical?) Funded by: Kay Graf (ECAP) – VLVnT 09, Athens – October 2009

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