Acoustic detection of high energy particle showers

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