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Acoustic detection of high energy particle showers

Acoustic detection of high energy particle showers. HU Berlin October 2003. Overview. Measurements proton beam lake Other experiments Mediterranian Bahamas Lake Baikal Future Conclusions. Motivation UHE neutrinos UHE n detection methods Acoustic detection thermoacoustic modell

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Acoustic detection of high energy particle showers

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  1. Acoustic detection of high energy particle showers HU Berlin October 2003

  2. Overview • Measurements • proton beam • lake • Other experiments • Mediterranian • Bahamas • Lake Baikal • Future • Conclusions • Motivation • UHE neutrinos • UHE n detection methods • Acoustic detection • thermoacoustic modell • signal expectations • Hardware • sensors • transmitters • ice preparation

  3. Motivation UHE cosmic rays: Absorption by CMBR:  GZK cutoff Absorption length:  no known sources • HiRes • AGASA Options: • Pin down cosmic rays • Detect neutrinos

  4. UHE n fluxes • guaranteed: • cosmogenic (GZK) neutrinos • possible: • AGN (model dependant) pCR+gsynch→X +p→n + ... • topological defects • Z-Burst (GeV g-problem) nUHE + nCNB→Z0→qq • neutrino oscillations: • ne : nm : nt=1:2:0 → 1:1:1

  5. UHE n detection methods EAS-Arrays : AGASA, AUGER E > 1019 eV, M  ? Satellits : OWL, EUSO E > 1019 eV , M  10 Tera t Radio : RICE, ANITA, SalSA, GLUE E > 1016 eV, M  10 Giga t Acoustic : AUTEC, SADCO (military) BAIKAL, Antares, NEMO, IceCube E > 1017 eV, M  10 Giga t

  6. n detection with AUGER under construction • technique: • air shower array • fluorescence telescopes • detector: • 1600 water cherenkov tanks • 3 telescopes ( 6 x 30° x 30° FOV) •  combine techniques • n shower properties: • CR interact at top of atmosphere • n also interact deep in atmosphere •  shower profile evolves •  separate young and old showers • only horizontal showers:

  7. n detection with EUSO planning phase • technique: • fluorescence telescope • satellite based • detector: • 200.000 pixel camera • 2m Fresnel lens • advantage: • huge observed volume (2•1012 t) • problem: • cloud coverage • only horizontal showers

  8. Detection of n induced cascades with RICE in operation • technique: • radio cherenkov telescope • frequency range (200 – 500 MHz) • detector: • 16 dipole receivers • spread over 200m x 200m x 200m • noise: • thermal • anthropogenic • limit: • 333.3 hours AGN AGN AGN TD GZK

  9. Detection of n induced cascades with IceCube • technique: • optical cherenkov telescope • south polar ice cap: • as a neutrino target • shielding against cosmic rays • detector: • 4800 Optical Modules • volume ≈ 1km3 • problem: • optimized for E ≈ 10 PeV • for cascades Veff ≈ Vgeom  too small for UHE neutrinos •  Add acoustic detection mode under construction IceTop pressure sensor

  10. Acoustic detection

  11. Thermoacoustic modell

  12. Signal amplitudes

  13. Noise

  14. Signal expectations

  15. Event rates -1 -1

  16. Piezoelectric ceramics • material: • lead zirkonium titanate (PXE5 = PZT) • pervoskit structure • polycrystalline • poling: • heat above Tcurie ≈ 300 ˚C • cool in strong E-Field (E ≈ 2 MV/m)  reorientation of polarization domains • sensitivity: d33≈ 500pC/N • typical signal: • 0.1 mV @ 1 mPa T > Tcurie T < Tcurie • shapes: • tubes • disks • cylinders • resonances: • mode • frequency

  17. Calibration of piezoceramics • stability: • stable with temperature, time, … • manufacturing variations • problem: • input impedance of voltmeter tdecharge= R•C ≈ 3 ms • charge integration

  18. Sensor design • amplifier: • high gain ( 80 dB )  Uout/Uin = 10.000 • low noise ( ≈ 8mV ) • housing: • impedance matching • high pressure • resonances housing amplifier piezoceramics brass head

  19. Sensors

  20. Sensor response: Amplitude

  21. Sensor response: Frequency

  22. Ice preparation

  23. Thé Svedberg Laboratoriet

  24. Experimental setup

  25. Results

  26. Confirmation of thermoacoustic modell:Temperature variation V.I. Lyashuk, A.A. Rostovtsev et al. , ITEP Moskau • expansion coefficient: • a = ∂r(T)/ ∂t = a(T) • signal: • a > 0 : compressional wave • a < 0 : contractional wave

  27. x|| proton beam Time [μs] Confirmation of thermoacoustic modell:pressure field V.I. Lyashuk, A.A. Rostovtsev et al. , ITEP Moskau • contributions: • A: constant energy loss  cylindrical wave • B-D: bragg peak  spherical wave • A-C: entrance point  spherical wave thermoacoustic modell • alternative mechanisms: • electrostriction • microbubbles Hunter et al., J.Acoust.Soc.Am 69(6),1981

  28. Zeuthen lake

  29. Zeuthen lake: Setup

  30. Frequency filtering

  31. ANTARES • Uni Erlangen: • 9 Persons (3 Postdoc, 1 PhD) • Hydrophones: • commercial • self-build (piezoceramics) • Transducers: • heating wire • laser • piezoceramics • Test facility: • temperature control • exact positioning • Simulation: • sensor response • array simulation piezoceramics electrodes EM shielding PU coating

  32. I/I0 [-dB] d [m] r [km] NEMO G.Riccobene, INFN LNS-Catania, Roma • Acoustic test site: • cable to shore • junction box • Commercial sensors: • low noise • good directivity • Investigations: • electronics and DAQ development • Amplifier noise investigations • cascade simulation • sound propagation • Ambient noise studies

  33. ITEP @ lake Baikal V.I. Lyashuk, A.A. Rostovtsev et al. , ITEP Moskau 50 m • detector: • 9 hydrophones below ice • 7 scintillation detectors on ice  EAS trigger • data taking: • March, 23 – April, 4 2003 • noise investigations • depends on sun shine / temperature  ice cracks • hydrophone development: • most sensitive hydrophones  selected piezoceramics Scintillation detectors 50 m 30 m H1 (4 m) B4 (4 m) B3 (4 m) G8 (9 m) G7 (9 m) B6 (4 m) H2 (9 m) H3 (14 m) H4 (19 m) hydrophones

  34. AUTEC Array Lethinen et al., Astropart. Physics 17 (2002 )279 • Atlantic Undersea Test • and Evaluation Center • detector: • 52 sensors • frequency band 1-50 kHz • 4.5 m above bottom surface • 2.5 km grid  250 km2 area • threshold: Eth≈ 1019

  35. SAUND @ AUTEC Justin Vandenbrouck, Stanford University • Study of Acoustic Ultrahigh energy Neutrino Detection • detector: • 7 hydrophones from AUTEC • signal source: • light bulbs  position reconstruction • data set: • 208 days  25•106 events • investigations: • triggering studies • digital filtering studies • sound refraction simulation • sensitive volume simulation

  36. SADCO Igor Zheleznykh, INR, Moscow AGAM • Sea Acoustic Detector of Cosmic Objects • detectors: • Kamchatka AGAM acoustic array (1500 hydrophones) • portable submarine antenna MG-10M (132 hydrophones)  deploy from oil platform • simulation: • shower (including LPM) • signals • absorption MG-10M

  37. Current status and activities • Theory: • seems to work  detailed verification • Simulation: • UHE cascade simulation • sound generation • sound propagation  media properties • sensor response • Existing arrays: • sufficient size and number of sensors • spacing to large • hydrophones not optimized • restrictions due to military use • New arrays: • commercial hydrophones too expensive  development of cheap sensors  future plans

  38. Uppsala 2004

  39. South pole 2004 / 2005

  40. South pole: measurements

  41. Conclusions • need for UHE neutrino detection • establish new technique • thermoacoustic sound wave generation exists • verify details • developed low price sensitive detectors  • can be improved • various approaches for different experiments  • combine international efforts • show feasibility of acoustic neutrino detection

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