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The evolution of high energy neutrino telescopes

The evolution of high energy neutrino telescopes

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The evolution of high energy neutrino telescopes

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  1. The evolution of high energy neutrino telescopes Christian Spiering DESY

  2. The evolution of high energy neutrino telescopes …a long march which has not yet reached its end.

  3. under- ground optical: - deep water - deep ice • air showers • radio • acoustics

  4. under- ground optical: - deep water - deep ice • air showers • radio • acoustics This talk will essentially address the optical telescopes deep under water and in ice. See the written version for the high-energy frontier and the corrersponding techniques

  5. Ann.Rev.Nucl.Sci 10 (1960) 63

  6. Ann.Rev.Nucl.Sci 10 (1960) 1

  7. Moisej Markov Bruno Pontecorvo M.Markov,1960: „We propose to install detectors deep in a lake or in the sea and to determine the direction of charged particles with the help of Cherenkov radiation“ Proc. 1960 ICHEP, Rochester, p. 578.

  8. Central interest: cross sections, W-mass … one of the main motivations for Reines‘ South Africa detector, the Kolar Gold Field Detector (India) and the Baksan scintillation detector. Early sixties: does the neutrino cross section saturate beyond 1 GeV (i.e. one would never measure atm. neutrinos with energies higher than a few GeV). The question was relaxed in the mid seventies:

  9. First measurement of atmospheric neutrinos Beside several ideas like e.g. • H. Uberall and C. Cowan, 1965 CERN Conf. on Experimental Neutrino Physics, p. 231 • Downward looking PM observing a 10 m thick water target, „possibly in ocean or a lake“ • V. Bogatyrev, Yad.Fiz 13 (1971) 336 • Three detectors each 107 tons of distilled water a several km depth, widely spaced  SN triangulation in 1965 detection of nearly horizontal atmospheric neutrinos by F. Reines in a South African Gold mine.

  10. DUMAND See also: A.Roberts: The birth of high-energy neutrino astronomy: a personal history of the DUMAND project, Rev. Mod. Phys. 64 (1992) 259. • 1973 ICRC, Reines, Learned, Shapiro, Zatsepin, Miyake: a deep water detector to clarify puzzles in muon depth-intensity curves • Puzzles faded away, but there remained the awareness that such a detector could also work as neutrino detector • The name: DUMAND (Deep Underwater Muon And Neutrino Detector), proposed by Fred Reines • 1975: First DUMAND Workshop in Washington State College • DUMAND Steering Committee, chaied by F.Reines, J. Learned, . A.Roberts

  11. Principle and capabilities   • Angular resolution of 1° possible  astrononomy • Energy resolution for muons is 50% at best, for 1 km track length

  12. The DUMAND Workshops • An unbelievable source of basic ideas (including crazy ones which are sometimes the most exciting) • 1976 Honolulu • 1978 Scripps • 1979 Khabarovsk/Baikal • 1978 Honolulu • Plus dedicated workshops on deployment, acoustic detection, signal procressing and ocean engineering

  13. Which physics? • UNDINE: UNderwater Detection of Interstellar Neutrino Emission • i.e. Supernova  too rarely to optimize an ocean detector for it ( IMB) • ATHENE: ATmospheric High-Energy Neutrino Experiment • Better with underground experiments • UNICORN: UNderwater Interstellar COsmic Ray Neutrinos • The high energy option • preferred option, but: how large are the fluxes ? •  think as big as possible ! A. Roberts:

  14. 1978: 1.26 km³ 22,698 OMs 1980: 0.60 km³ 6,615 OMs 1982: 0.015 km³ 756 OMs 1988: 0.002 km³ 216 OMs DUMAND-II

  15. Financial and technological reality !

  16. DUMAND-II (The Octagon) • 9 strings • 216 OMs • 100 diameter, 240 m height • Depth of bottom: 4.8 km • Lowest OM 100 m above bottom

  17. or

  18. Point sources, DUMAND-II (0.002 km³) expectations in the eighties !!! Note: in 1989, the only proven TeV  source was the Crab SNR! With these assumptions, a km³ detector would have discovered 5-50 (worst scenario) up to several ten thousand events (best scenario) per source

  19. Diffuse sources, DUMAND-II (0.002 km³) expectations in the eighties

  20. Technology boosts • Optical fibers with < 12 db attenuation over 40-km length and data rates of hundreds of MBaud (Nobel prize 2009!) • Appearance of 16“ Hamamatsu PMT • Appearance of 14“ „smart“ Philips PMT JOM Japanese Optical Module EOM European Optical Module

  21. 1987: The SPS „Short Prototype String“ • 1982-87: a series of 14 cruises, with two lost strings • 1987: success ! • depth-intensity curve • angular distributions • attenuation lenght (4722 m)

  22. DUMAND after the SPS: • 1989: HEPAP supports DUMAND-II • 1990: DOE allocates funds for DUMAND-II • Further financial cuts  TRIAD (3 strings) • 1993: shore cable laid • December 1993: deployment of first string and connection to junction box. Failure after several hours • 1995: DUMAND project is terminated

  23. Russia • Very active during early DUMAND workshops (Chudakov, Berezinsky, Bezrukov, Zhelesnykh, Petrukhin) • Kicked out of DUMAND after Russian Afghanistan invasion A. Roberts: • 1980: Chudakov proposes exploration of Lake Baikal as possible site for a neutrino telescope • 1981: start of site investigations at Lake Baikal (Domogatksy, Bezrukov) • Exploration of Atlantic, Black Sea, Indian Ocean, Pacific and Mediterranean sites (Zheleznyk, Petrukhin) • A. Roberts: „Communication among these groups is not very good“

  24. The Lake BAIKAL experiment Bezrukov, Domogatsky, Berezinsky, Zatsepin G. Domogatsky • Largest fresh water reservoir in the world • Deepest Lake (1.7 km) • 1981: first site explorations & R&D • Choosen site 3.6 km from shore, 1.3 km depth

  25. Ice as a natural deployment platform

  26. … and its mis-interpretation: A. Roberts:

  27. Lake Baikal: the eighties • 1984: first stationary string • Muon flux measurement • 1986: second stationary string (Girlyanda 86) • Limits on GUT magnetic monopoles • All that with 15-cm flat-window PMT FEU-49 • Development of a Russian smart phototube (Quasar)

  28. Towards NT-200 4-string stage (1996) J. Learned to C.Spiering: „Congratulations for winning the 3-string race!“ (NT-36 vs TRIAD vs AMANDA) • 1988: Germany joins • 1989/90: design of NT-200 • 1993 + 1994: NT-36 - 18 channels at 3 strings - first underwater array - first 2 neutrino candidates • 1995: NT-72 - 38 channels at 4 strings • 1996: NT-96 - 48 channels at 4 strings - clear neutrinos • 1998: NT-200 - 96 channels at 8 strings

  29. NT-200 2 PMTs in coincidence to surpress background 3600 m 1366 m NT-200

  30. NT200 results 396  candidates • Atmospheric neutrinos • WIMP search • Diffuse neutrino fluxes • Skymap • GRB coincidences • Magnetic monopoles Amanda 4 years Baikal 5 years

  31. NT200+ 3600 m 1366 m NT200 For searches of diffuse neutrino fluxes, the small NT200 could compete with the much larger Amanda by monitoring a large volume below the detector. NT200+ fences this volume. construction 1993-1998 NT200 • NT200+ • upgrade 2005/06 • 4 times better sensitivity than • NT200 for PeV cascades • - basic cell for km3 scale detector 140 m

  32. Gigaton Volume Detector, GVD L~ 350 m R ~ 60 m • Sacrifice low energies (muon threshold ~ 10 TeV) • Protoype strings being tested • Modular clusters, stepwise installation > 2012 • ~ 2000 optical modules (conventional PMs) 12 clusters of strings NT1000: top view

  33. All other deep water/ice detector projects started around 1990 or later.In the eighties /early nineties, shallow detectors have been proposed but never built. On the other hand, deep underground detectors reached their full blossom:- solar neutrinos- supernova neutrinos- limits on proton decay- first hints to neutrino oscillations- sky maps

  34. Shallow detector projects • Advantages: easy access, less challenging environment • Disadvantages: huge background, not expandable • GRANDE • Shallow water, Lake, Arkansas, H. Sobel (Irvine) • LENA • Artificial water pool, Gran Sasso, M.Koshiba • SINGAO • Resistive Plate Chambers, Italy/UK • Swedish lakes • Early nineties, before Sweden joined Amanda

  35. Underground Detectors • KGF • Baksan • FREJUS • Soudan • IMB • Kamiokande Superkamiokande • MACRO e.g. MACRO, 1356 upgoing muons ~ 1000 m²

  36. Neutrino oscillations, proton decay • Deficit of solar neutrinos (see Kai Zuber‘s talk) • Deficit of atmospheric neutrinos as function of distance and energy • Stringent limits on proton life time |m232| = (2.6±0.2) ·10-3 eV2 |m221| = (8.3±0.3) ·10-5 eV2 12= 33.9º±1.6º 23= 45º±3º 13< 9º

  37. 1990-2000: revisiting the expectations • Underground detectors, 1000 m², only for young Supernovae in our Galaxy (Berezinsky) • New estimates on neutrinos from Supernova remnants and other galactic sources based on observations with Whipple and HEGRA • For supernova remnants, microquasars, extragalactic sources: need detector of order 1 km³. • The Waxman-Bahcall bound • The Mannheim-Protheroe bound • GRB as sources of cosmic rays and neutrinos

  38. Diffuse Fluxes 2002  bound MPR bound WB bound This model was down- corrected by a factor of 20 in 2005.

  39. The ice option F. Halzen • 1988: Pomerantz workshop, NSF Science and Technology Center for the South Pole (A. Westphal, T.Miller, D. Lowder, B. Price) • E. Zeller (Kansas) suggests to F. Halzen radiodetection of neutrinos in Antarctic ice • 1989: attempt of Westphal and Lowder to measure ice transparency in existing boreholes • Jan. 89, ICRC, Adelaide: Decide to propose Amanda (B. Price, D. Lowder, S. Barwick, B. Morse, F. Halzen, A. Watson) • 1990: Morse et al. deploy PMTs in Greenland ice

  40. Nature Sept 91

  41. South Pole • 1991/91 first small PMTs deployed • Results consistent with 25 m absorption length Heaters and pumps to melt the holes

  42. South Pole 93/94 AMANDA-A

  43. 1 km 2 km 93/94 40 m Catastrophal delay of light between strings 20 m away! (µsec instead of 100 nsec)

  44. Explanation remnant bubbles which are disapppearing with increasing depth.

  45. Amanda B4 1995: DESY and Stockholm build ~ 100 modules, 86 deployed in the season 95/96 at 1450-1950 m depth The DESY crew