The evolution of high energy neutrino telescopes Christian Spiering DESY The evolution of high energy neutrino telescopes …a long march which has not yet reached its end. underground optical: - deep water - deep ice - air showers - radio - acoustics underground 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 Ann.Rev.Nucl.Sci 10 (1960) 63 Ann.Rev.Nucl.Sci 10 (1960) 1 Moisej Markov M.Markov, Bruno Pontecorvo 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. 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: 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. 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 Principle and capabilities Angular resolution of 1° possible astrononomy Energy resolution for muons is 50% at best, for 1 km track length 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 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 A. Roberts: UNICORN: UNderwater Interstellar COsmic Ray Neutrinos – The high energy option – preferred option, but: how large are the fluxes ? – think as big as possible ! 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 Financial and technological reality ! 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 p p .... e e p n or p 0 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 Diffuse sources, DUMAND-II (0.002 km³) expectations in the eighties 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 JOM Japanese Optical Module Appearance of 14“ „smart“ Philips PMT EOM European Optical Module 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 (4722 m) 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 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“ 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 Ice as a natural deployment platform … and its mis-interpretation: A. Roberts: 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) Towards NT-200 J. Learned to C.Spiering: 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 „Congratulations for winning the 3-string race!“ (NT-36 vs TRIAD vs AMANDA) 4-string stage (1996) NT-200 2 PMTs in coincidence to surpress background NT-200 NT200 results 396 candidates Atmospheric neutrinos WIMP search Diffuse neutrino fluxes Skymap GRB coincidences Magnetic monopoles 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 12 clusters of strings NT1000: top view Sacrifice low energies (muon threshold ~ 10 TeV) Protoype strings being tested Modular clusters, stepwise installation > 2012 ~ 2000 optical modules (conventional PMs) L~ 350 m Gigaton Volume Detector, GVD 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 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 Underground Detectors KGF Baksan FREJUS Soudan IMB Kamiokande Superkamiokande MACRO e.g. MACRO, 1356 upgoing muons ~ 1000 m² Neutrino oscillations, proton decay Deficit of solar neutrinos (see Kai Zuber‘s talk) Deficit of atmospheric neutrinos as function of distance and energy |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 Stringent limits on proton life time 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 Diffuse Fluxes 2002 This model was downcorrected by a factor of 20 in 2005. bound MPR bound WB bound 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 Nature Sept 91 South Pole 1991/91 first small PMTs deployed Results consistent with 25 m absorption length Heaters and pumps to melt the holes 93/94 40 m 1 km Catastrophal delay of light between strings 20 m away! (µsec instead of 100 nsec) 2 km Explanation remnant bubbles which are disapppearing with increasing depth. Amanda B4 1995: DESY and Stockholm build ~ 100 modules, 86 deployed in the season 95/96 at 1450-1950 m depth The DESY crew B4: first 2 neutrinos Drilling Hot water drilling AMANDA B10 IceCube will work ! 1 km 96/97 AMANDA - B10 2 km 120 m NATURE 2001 Skyplot of the very first 17 Nu candidates in B10 B10 skyplot published in Nature 2001 97/98 3 long strings study deep and shallow ice for future IceCube 0.02 1 km Scattering coefficient (1/m) vs. depth 2 km 120 m 0.1 0.5 AMANDA-II 1 km 99/00 2 km 200 m Ocean Water AMANDA results δ=90º Max Significance δ=54º, α=11.4h Diffuse fluxes 3.38σ Point sources Neutrinos from GRB WIMP searches Magnetic Monopoles 0h 24h Cosmic rays SN monitoring Skymap from 7years AMANDA: no significant excess …. No significant excess found The one intriguing coincidence …. WHIPPLE Arrival time of neutrinos from the direction of the AGN ES1959+650 Flux of TeV photons (arb. units) 3 2 1 0 May 2000 2001 2002 2003 Year June July IceCube Observatory 07/08: 18 06/07: 13 05/06: 8 04/05: 1 08/09: 19 strings Remaining: 22 IceCube Strings 5 DeepCore Strings complete in January 2011 Shadow of the Moon Absolute pointing 1° Angular resolution 1° Downward muons, max. 28° above horizon, median energy of primary parent ~ 30 TeV Cosmic Rays 0.5° 8 months IceCube 40 strings 90 Large-scale anisotropy of downgoing muons 0 24h 12 TeV IceCube -90 90 (40 strings 2008) anisotropies on the per-mille scale 24h 0 126 TeV (skymap in equatorial coordinates) -90 Compare to Northern hemisphere Tibet air shower array Compton-Getting effect ? Heliosphere effect ? Nearby pulsar ? Interstellar magnetic field ? First observation on Southern hemisphere adds important piece of information. Simulation (Lallement et al. Science 2005) MILAGRO First look above horizon (IceCube 2007, 22 strings) PeV-EeV range Northern hemisphere Southern hemisphere Point Sources: The Progress factor 1000 in 15 years ! Diffuse Fluxes: The Progress Baikal/ Another factor 1000 ! Mediterannean projects NESTOR (since 1991) „Amanda-sized“ -- under construction (?) ANTARES (since 1996) „Amanda sized“ -- data taking NEMO: R&D for km3 project Since 2003: km3 initiative KM3NeT 2400m ANTARES NEMO 3400m 4100m NESTOR NESTOR 1991: first site studies 1992: first muon count 1992-2001: many ocean tests, build lab and infrastructure 2000: cable to site 2003: deploy first floor. Cable failure after a few weeks Compare to 2000 declared plan: – deploy full tower 2003 – deploy 6 more towers 2005 ANTARES Installation: Junction Box - Dec 2002 Line 1 - March 2006 Line 5-1 - Dec 2007 Line 11-12 - May 2008 Antares results NEMO R&D for KM3NeT - 4-floor tower in 2006 - full tower end of 2009 KM3NeT Recommendations KM3NeT 2001/02: High Energy Neutrino Astrophysics Panel – – – – – High physics interest Need km³ scale Need both hemispheres No more than 1 Northern detector Timely formation of Northern hemisphere deep water detector is encouraged 2008: ApPEC – The priority project for high energy neutrino astronomy is KM3NeT. – Encouraged by the significant technical progress of recent years, the support for working towards KM3NeT is confirmed. – Resources for a Mediterranean detector should be pooled into a single optimised design for a large research infrastructure, with installation starting in 2012. – The sensitivity of KM3NeT must substantially exceed that of all existing neutrino detectors including IceCube. KM3NeT Site Size Configuration Technology Deployment 2 km Construction Data taking Design decision …a long march which has not yet reached its end.