S. E. Tzamarias Hellenic Open University. BAIKAL-ANTARES Mediterranean km 3 Neutrino Telescope

Transcription

1 S. E. Tzamarias Hellenic Open University BAIKAL-ANTARES ANTARES-NEMO-NESTORNESTOR Mediterranean km 3 Neutrino Telescope

2 Second Generation Neutrino Telescopes E μ > 5-100Gev A eff. ~0.1-1km 2 ANTARES NEMO NESTOR BAIKAL AMANDA - IceCube

3 Baikal Neutrino Telescope 3600 m 4 cables x 4km to shore. 1070m depth 1366 m

4 Ice as a natural deployment platform Ice stable for 6-8 weeks/year: Maintenance & upgrades Test & installation of new equipment Operation of surface detectors (EAS, acoustics, )

5 Baikal Neutrino Telescope C. Spiering

6 -8 strings: 72m height optical modules - pairwise coincidence 96 space points - calibration with N-lasers - timing ~ 1 nsec - Dyn. Range ~ 1000 pe Effective area: 1 TeV ~2000 m² Eff. shower volume: 10TeV ~0.2Mt 15 inch PMTs QUASAR facing downwards (sedimentation-50% of sensitivity lost in 150 days) 6

7 Atmospheric Muon-Neutrinos 3-dimensional reconstruction 84 events ΔΨ ~ 3 Thresh. ~ 15 GeV Skyplot (galactic coordinates) BG dominated bin Neu2004-Zh. Dzhilkibaev 7

8 WIMP Neutrinos from the Center of the Earth Angular νdistributions (502 days, NT-200) χ + χ b + b 24 events - experiment 36.6 events - expected without oscillations 29.7 events - expected with oscillations C + μ + ν μ W + + W - 8

9 High Energy -Cascades ν NT-200 μ (BG) Look for upward moving light fronts. Signal: isolated cascades from neutrino interactions Background: Bremsshowers from h.e. downward muons large effective volume Final rejection of background by energy cut (N channel ) 9

10 Model Prediction Φ ν = AE -γ 1.5 Data μ atm cut cut

11 Diffuse flux of ν e, ν τ, ν μ : cascades Neu2004-Zh. Dzhilkibaev The 90% C.L. Limits Obtained With NT-200 (780 days) DIFFUSE NEUTRINO FLUX (Ф ν ~ E -2, 10 TeV < E < 10 4 TeV) ν e :ν μ :ν τ = 1 : 2 : 0 (AGN) ν e :ν μ :ν τ = 1 : 1 : 1 (Earth) E 2 Ф ν < GeV cm -2 s -1 sr -1 E 2 Ф ν < GeV cm -2 s -1 sr -1 (AMANDA04) W-RESONANCE ( E = 6.3 PeV, σ = cm 2 ) Ф ν e < (cm 2 s sr GeV) -1 Ф ν e < (cm 2 s sr GeV) -1 (AMANDA04)

12 Fast monopoles (β>0.8) N γ (λ) = n 2 (g/e) 2 N γμ (λ) = 8300 N γμ (λ) g = 137/2, n = 1.33 Background - atmospheric muons N hi t > 35 ch, upward-going monopole - Search for monopoles 780 livedays Monopole limit (90% C.L.) Search for slow massive monopoles (10-5 < β < 10-3 ) σ cat =0.17σ 0 /β 2, 10 5 <β<10 3 M+p M+e + (+π ), Ν γ ~10 5 NT detection of massive bright objects (GUT-monopoles, nuclearites, Q-balls ) monopole trigger: N hit >4 within dt=500μsec selection requirements - N ch >1 with N hit >14

13 A Gigaton (km3) Zh. Dzhilkibaev-Neu2004 Detector in Lake Baikal. Sparse instrumentation: 91 strings with 12 OM = 1308 OMs effective volume for 100 TeV cascades ~ km³! muon threshold between 10 and 100 TeV

14 Gisela Anton-Neu2004 ANTARES Site Location: Toulon (France) Depth: 2500 m 42º50 N, 6º10 E Submarine Cable Shore station : La Seyne sur Mer Control room: Institute Michel Pacha (La Seyne sur Mer)

15 Water quality parameters water transparency: λ abs ~ 60±8 m (470 nm) λ abs ~ 26±2 m (370 nm) light scattering : λ eff ~ 300 m (470 nm) λ eff ~ 100 m (370 nm) λ eff = 1 λ scat cosθ

16 12lines 25 storeys / line 3 PMTs/ storey 900 PMTs Detector design (1) a storey 14.5 m 350 m to be deployed by m 40 km to shore ~70 m Anchor/line socket Submarine links Junction Box

17 Prototype Lines operated in 2003 J. Carr - VLVNT Workshop Prototype Sector Line (PSL) Probe for Sound velocity Mini Instrumentation Line (MILL) Profiler for Sea currant (ADCP) 5 Storeys of Optical Modules Probe for salinity and temperature (CTD) hydrophone Junction Box LED Beacon hydrophones Seismograph Anchor with electronics containers Laser Beacon Link Cables

18 Gisela Anton-Neu2004 Submarine cable connection March 2003

19 Gisela Anton-Neu2004 PSL & MIL operations 2003 Sea operations PSL MIL Deployment Connection Recovery Lines operations Power distribution Remote-control Dec 02 Feb 03 Mar 03 Mar 03 Jul 03 May 03 Junction box operates fine Very functional Acquisition and digital transfer 130 Gb on disk The dark side Water leak in 1 LCM Broken fiber in EMC Mismatch O-ring/hole dimensions Inappropriate protective tube used by manufacturer New connector New EMC

20 Gisela Anton-Neu2004 Examples for PMT rates (short time) Rate (khz) 10min 10min time rates due to : radioactive 40 K and bioluminescence

21 Long time rate variation (spring 2003) Gisela Anton-Neu2004 baseline rate (khz) baseline rate: rate averaged during 15 min burst fraction: percentage of time with rate > 1.2 baserate burst fraction time (days) time April - May - June 2003 correlation between burst fraction and sea current velocity observed

22 J. Carr - VLVNT Workshop Correlation with Bioluminescence Counting rate in PMT (khz) Sea current ( cms/sec)

23 Muon tracks (from 1999 campaign) Gisela Anton-Neu2004

24 J. Carr - VLVNT Workshop ANTARES 12 line detector 2006 >2006 KM 3

25 NEMO - Towards the km3 neutrino telescope R&D phase ( ) Site selection and characterization Several sites close to the italian coasts have been studied. A site close to Capo Passero (Sicily) at 3500 m with optimal characteristics has been identified for the installation R&D activities Development of specific ASICS for the underwater front end electronics Large area hybrid photomultipliers Development of deep sea instrumentation Feasibility study for the km3 detector All the critical components and the deployment procedures have been examined A preliminary project for a km3 detector has been developed Phase 1: Advanced R&D and prototyping ( ) Realization of a detector subsystem including all critical components The system will be installed off Catania at the Underwater Test Site of the LNS Towards the km3 neutrino telescope (EU Design Study)

26 Site exploration activities Since 1998 continuous monitoring of a site close to the coast of Sicily More than 20 sea campaigns on the site to measure water optical properties optical background deep sea currents nature and quantity of sedimenting material Other sites explored for optical properties Two sites in the Southern Thyrrenian Sea (Ustica and Alicudi) Toulon (ANTARES site), in collaboration with Antares Lake Baikal

27 The Capo Passero site Site optical and oceanographical characteristics Absorption lengths (~70 nm) are compatible with optically pure sea water values Measured values are stable troughout the years (important: variations on La and Lc will directly reflect in changes of the detector effective area) Optical background is low (consistent with 40 K background with only rare occurrences of bioluminescence bursts) The site location is optimal (close to the coast, flat seabed, far from the 50 NM shelf break and from canyons, far from important rivers) Measured currents are low and regular (2-3 cm/s average; 12 cm/s peak) 3500m depth Sedimentation rate is low No evidence of recent turbidity events

28 Preliminary project for a km 3 detector Schematic detector layout Reference layout used for the feasibility study 180 m 1 main Junction Box 8 secondary Junction Boxes 64 Towers Detector architecture Reduce number of structures to reduce connections and allow underwater operations with a ROV non homogeneous sensor distribution Modularity 16 storeys with 4 OM (active height 600 m) 180 m 4096 OM Total instrumented volume 1 km 3

29 Deployment of the tower The NEMO tower

30 Neutrino Extended Submarine Telescope with Oceanographic Research The NESTOR Neutrino Telescope Site

31 Site characteristics a broad plateau: 8x9 km 2 in area, 7.5 nautical miles from shore depth: ~4000m transmission length: m at λ=460 nm underwater currents: <10 cm/sec measured over the last 10 years optical background: ~50 khz/om due to K40 decay, bioluminescence activity (1% of the experiment live time) sedimentology tests: flat clay surface on sea floor good anchoring ground.

32 NESTOR TOWER Detector Architecture 32 m diameter 30 m between floors 144 PMTs Energy threshold as low as 4 GeV m 2 Effective Area for E>10TeV

33 2003 Successful deployment of one NESTOR star with 12 Optical Modules to 4000m using the cableship RAYMOND CROZE (FranceTelecom) 29 th of March: The first deep sea muon data transmitted to shore

34 Data from a depth of 4000 m Bioluminescence Contribution to the Total Trigger Rates Bioluminescence Occurs for the 1.1% ± 0.1% of the Active Experimental Time Total Trigger Rates Bioluminescence Contribution to the Total Trigger Rates Experimental Trigger Rates from Periods Without Bioluminescence

35 Data from a depth of 3800 m Trigger Studies Data Collected with 4fold Majority Trigger Experimental Points M.C. Estimation (Atmospheric muons + K 40 )

36 c (1/N)dN/dcos(θ) Comparison with Okada model χ 2 probability: 52% M.C. Prediction Data Points Zenith Angle (degrees)

37 Apply quality cuts to improve resolution Monte Carlo Studies Selection Criteria χ 2 probability > 0.1 track selection according to the photon-likelihood more than 4 p.e.s per hit per track impact parameter > 6 meters

38 Reconstruction Accuracy χ 2 probability > 0.1 track selection according to the photon-likelihood more than 4 p.e.s per hit per track impact parameter > 6 meters Standard Deviation: 12 o 8.5 o Standard Deviation: 11 o

39 Determination of Cosmic Muon Flux dn α o dω dt ds = Icosθ I o α =4.7± 0.5 I = ± cm s sr o Contribution to the Systematic Errors (% of the estimation) Source I o α Selection criteria 2% 2% Reweighting and binnining ~0% ~0% α Energy dependance of the zenith angle distribution Functional parametrization of the muon flux 3% 4% ~0% ~0%

40 Comparison with other experiments and phenomenological predictions Edgar V. Bugaev, et al, Physics Review D58, (1998). α =4.7± 0.5( stat) ± 0.2( syst) I = ± ( stat) ± ( syst)cm s sr o

41 NESTOR Floors m 2 effective area for E>10TeV 2006: 15% of a Km 2 NESTOR Detector

42 The KM3NeT Project Design Study for a Deep Sea Facility in the Mediterranean for Neutrino Astronomy and Environmental Sciences Institutes participating in the Design Study: Cyprus: Univ. Cyprus France: CEA/Saclay, CNRS/IN2P3 Marseille, CNRS/IN2P3 Strasbourg, Univ. Haute Alsace Germany: Univ. Erlangen, FTZ Univ. of Kiel Greece: Hellenic Open Univ., NCSR Demokritos, NOA/Nestor Inst.,Univ. Athens, Univ. Crete, Univ. Patras Italy: INFN (Bari, Bologna, Catania, LNS Catania, LNF Frascati, Genova, Messina, Pisa, Roma-1) Netherlands: NIKHEF (Univ. Amsterdam, Free Univ., Univ. Utrecht, Univ. Nijmegen) Spain: IFIC (CSIC, Univ. Valencia), U.P. Valencia United Kingdom: Univ. Leeds, Univ. Sheffield, Univ. Liverpool

43 HENAP Report to PaNAGIC, July 2002: The observation of cosmic neutrinos above 100 GeV is of great scientific importance a km 3 -scale detector in the Northern hemisphere should be built to complement the IceCube detector being constructed at the South Pole. The detectors should be of km 3 -scale, the construction of which is considered technically feasible.

44 Sky Observable by Neutrino Telescopes (Region of sky seen in galactic coordinate assuming 100% efficiency for 2π down) South Pole Mediterranean Mkn 421 Mkn 501 CRAB Not seen Mkn 501 CRAB SS433 Not seen SS433 GX339-4 Galactic Centre VELA Need Neutrino Telescopes in both hemispheres to see whole sky

45 Physics Perspectives of KM3NeT South Pole Mediterranean Astrophysics via high-energy neutrino observation Production mechanisms of high-energy neutrinos in the universe (acceleration mechanisms, top-down scenarios,... ) Investigation of the nature of astrophysical objects Origin of cosmic rays Indirect search for dark matter Associated science

46 Point Sources - Sensitivities MACRO + SK + AMANDA-B10 AMANDA AMANDA + IceCube + ANTARES + NESTOR IceCube + KM3NeT Ch. Spiering, astro-ph/

47 Objectives and Scope of the KM3NeT Design Study Establish path from current projects to KM3NeT critical review of current technical solutions thorough tests of new developments assessment of quality control and assurance explore and establish possible cooperation with industry envisaged time scale of design, construction and operation poses stringent conditions

48 Design Study Target Values Detection principle: water Cherenkov Location in Europe: in the Mediterranean Sea Detection view: maximal angular acceptance for all possible detectable neutrino signals including down-going neutrinos at VHE Angular resolution: close to the intrinsic resolution (<~0.1 degrees for muons with E ν >~ 10 TeV) Detection volume: 1 km 3, expandable Lower energy threshold: a few 100 GeV for upward going neutrinos with possibility to go lower for ν from known point sources Energy reconstruction: within factor of 2 for muon events Reaction types: all neutrino flavours Duty cycle: close to 100% Operational lifetime: >= 10 years But these parameters need optimisation!

49 Technical Design of the ν Telescope Cost-effectiveness: <~ 200 MEuro per km 3 Architecture: strings vs. rigid towers vs. flexible towers vs. new solutions Photo detectors Mechanical solutions Readout: electronics, data acquisition, data transport Calibration and slow control Cables and connectors: dry vs. wet Simulations: design optimisation and assessment; impact of environmental conditions Construction of the telescope within 5 years after end of the Design Study Detailed assembly procedures Distributed production lines Evaluation of logistics needs Quality control and assurance model

50 Installation and Maintenance Deployment: fast procedures; parallelisation of operations Shore infrastructure: supply units; on-shore computing; internet connection Maintenance: flexible, low-cost access to sea-operation equipment; rapid recovery procedures; cost-effective repair options Exploitation Model facility exploited in multi-user and interdisciplinary environment Reconstructed data will be made available to the whole community Observation of specific objects with increased sensitivity will be offered (dedicated adjustment of filter algorithms) Close relation to space-based observatories will be established (alerts for GRBs, Supernovae etc.) Plug-and-play solutions for detectors of associated sciences Operation Model: centralised services for tasks exceeding the capacity of single institutes Funding and Governance Associated Sciences: Biology, Oceanography, Environmental sciences, Geology and geophysics...

51 Detector Architecture A number of different solutions exist: Homogeneous strings Towers Nested arrays Deployment strategies Plots from D. Zaborov

52 AC or DC, shore to detector? Redundancy? (>1 cable) Wet-mateable vs. dry-mateable (underwater) connectors Reduce number of connectors due to relatively high cost Power, Mechanics 200 m Tower 1400 m 200 m Primary JB Secondary JB Power distribution scheme (how many junction boxes, hierarchy, etc.) Materials: anti-corrosion, pressureresistant, water blocking New ideas: encapsulation Main electro optical cable

53 Sea Operations Different deployment strategies, central star topology or/and serial topology a la NESTOR Possible self connecting systems that obviate the need for ROVs/submarines

54 Photodetection Other wild ideas include increasing photocathode area with arrays of small PMTs packed into pressure housings - low cost! Also on the wish list possibility of determining the photon direction via, e.g. Multi-anodic PMTs plus a matrix of Winston cones R R

55 Calibration Three main areas: Timing calibration - high accuracy needed for relative calibration - determines angular resolution at high energies. Affected by choice of photosensor, dispersion in the medium, electronics delays, etc. Will require distributed clock system plus pulsed light sources Monitoring of positioning of optical detector elements, also important in determining overall detector performance Amplitude calibration - gain from 40 K. Scalability of current calibration systems to cubic kilometre

56 Readout and Data Transfer Due to the presence of 40 K and bioluminescence the data rate from a km 3 detector will be high - estimated at Gb/s Questions addressed included: Optimal data transfer to shore (many fibres + few colours, few fibres + many colours, etc.) How much processing to be done at the optical module Analogue vs. digital OMs - implies differing approaches to design of front end electronics Data filtering will play an important role One possible data distribution concept Also discussed: application of current PP GRID technologies to some of these open questions

57 U. Katz What is our aim?: a deep-sea km 3 -scale observatory for high energy neutrino astronomy and associated platform for deep-sea science Why we need an FP6 Design Study?: to enable the European neutrino astronomy community to prepare for the timely and cost-effective construction of the next-generation neutrino telescope Why we need it now?:... both in view of the size of the enterprise and of a timely competition with IceCube, the Committee finds it urgent that a single coherent collaboration be formed,... Recommendation from ApPEC peer review meeting, Amsterdam, 3-4 July 2003 The Mediterranean Sea offers optimal conditions water quality, depth, temperature,... existing infrastructure current expertise for sea water ν telescopes concentrated in European countries a perfect stage for a large Europe-led science project

58 KM3NET: Work Packages Divided project up into work packages Request for funding for 3 years - end product will be a TDR for km3 in the Med Astroparticle Physics Information Technology Risk Assessment Quality Assurance Physics Analysis Shore and deep-sea structure Resource Exploration System and Product Engineering Sea surface infrastructure Associated Science A TDR for a Cubic Kilometre Detector in the Mediterranean

59 KM3NeT Milestones End 2004 Start design study Mid 2006 Conceptual design ready End 2007 Technical design ready Construction 2009 XXXX Operation