1 / 51

Emilio Migneco

Emilio Migneco. Erice ISCRA School 2004. Future cubic kilometer arrays. Topics. Future cubic kilometer arrays for HE neutrino astronomy Review of existing detectors and projects Future detectors: impact of site parameters architecture simulations and expected performances

chung
Download Presentation

Emilio Migneco

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Emilio Migneco Erice ISCRA School 2004 Future cubic kilometer arrays

  2. Topics Future cubic kilometer arrays for HE neutrino astronomy Review of existing detectors and projects Future detectors: impact of site parameters architecture simulations and expected performances experimental challenges

  3. atmospheric muon ~5000 PMT The observation of TeV neutrino fluxes requires km2 scale detectors Cherenkov light neutrino muon Connection to the shore depth >3000m neutrino

  4. Neutrino telescopes brief history 80’s: DUMAND R&D 90’s: BAIKAL, AMANDA, NESTOR 2k’s: ANTARES, NEMO R&D 2010: ICECUBE Mediterranean KM3 ? BAIKAL Pylos Mediterranean km3 DUMAND La Seyne Capo Passero AMANDA ICECUBE

  5. The present of HE neutrino detectors Two experiments have recorded HE neutrino events and are currently taking data: BAIKAL in Sibiria AMANDA in South Pole

  6. Baikal-NT: 192 OM arranged in 8 strings, 72 m height effective area >2000 m2 (E>1 TeV) The pioneer experiment: BAIKAL 3600 m 1366 m Depth max 1300m Blue light absorption length ~20 m No 40K but high bioluminescence rate successfully running since 10 years atmospheric neutrino flux measured

  7. The largest detector up to date: AMANDA AMANDA-II 19 strings 677 OMs Depth 1500-2000m Optical Module Effective Area  104 m2 (E TeV) Angular resolution  2° See Silvestri’s talks

  8. The future of underice neutrino telescope: ICECUBE The technology for underice detectors is well established. The next step is the construction of the km3 detector ICECUBE.

  9. ICECUBE Concept/Development Implementation Operations & Maintenance $M $70 IceCube Funding, by Phase $60 $50 $40 $30 $20 $10 $0 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 5 MW 80 strings (60 PMT each) 4800 10” PMT (only downward looking) 125 m inter string distance 16 m spacing along a string Instrumented volume: 1 km3 (1 Gton) IceCube will be able to identify  tracks from  for E > 1011 eV cascades from e for E > 1013 eV  for E > 1015 eV The enhanced hot water drill

  10. ICECUBE vs. AMANDA Eµ= 6 PeV Eµ= 10 TeV Halzen AMANDA Measure energy by counting the number of fired PMT. (This is a very simple but robust method) Expected energy resolution 0.3 in log(E)

  11. Expected ICECUBE perfomances Aeff / km2 cos  Halzen • above 1 TeV resolution ~ 0.6 - 0.8° for most zenith angles Effective area vs. zenith angle (downgoing muons rejected)

  12. Scientific motivations for two km3 detectors • There are strong scientific motivations that suggest to install two neutrino telescopes in opposite hemispheres : • Full sky coverage • The Universe is not isotropic at z<<1, observation of transient phenomena • Galactic Center only observable from Northern Hemisphere PANAGIC HENAP recommendations 2002 The most convenient location for the Northern km3 detector is the Mediterranean Sea: vicinity to infrastructures good water quality good weather conditions for sea operations

  13. Observation time 1.5  sr common view per day ICECUBE QSO TeV sources Galactic centre Mediterranean km3 Galactic coordinates

  14. The Mediterranean km3 detector potentials and payoffs The underwater telescope can be installed at depth  3500 m Muon background reduction Light effective scattering length (>100 m) is much longer than in ice (20 m) Cherenkov photons directionality preserved Light absorption length in water (70 m) is smaller than in ice (100 m) Less Cherenkov photons detected 40K decay in water + bioluminescence Optical background and dead time increased Sediments and fouling Optical modules obscuration  maintenance • Structures can be recovered: • The detector can be maintained • The detector geometry can be reconfigured

  15. The Mediterranean km3 There are three collaborations active in the Mediterranean Sea: ANTARES, NEMO and NESTOR Toulon 2400 m ANTARES NEMO NESTOR Capo Passero 3400 m Pylos 3800:4000 m

  16. NESTOR aims at installing a “tower” equipped with optical modules of  20.000 m2 detection area. NESTOR Resvanis 1 floor equipped with 12 PMTs deployed at 3800 m depth in March 2003 745 atmospheric muon events reconstructed

  17. 14.5 m ~70 m Anchor/line socket ANTARES is installing a 0.1 km2 demonstator detector close to Toulon to be deployed by 2005-2007 • 12 lines • 25 storeys / line • 3 PMTs / storey • 900 PMTs ANTARES See Sulak’s talk 350 m 40 km to shore 100 m Junction Box Submarine links

  18. NEMO • The NEMO Collaboration is dedicating a special effort in: • development of technologies for the km3 (technical solutions chosen by small scale demostrators are not directly scalable to a km3) • search, characterization and monitoring of a deep sea site adequate for the installation of the Mediterranean km3.

  19. The NEMO test site in Catania Shore laboratory port of Catania A fully equipped facility to test and develop technologies for the Mediterranean km3 Underwater test site: 21 km E offshore Catania 2000 m depth cable: 10 OF; 6 conductors 2004-2006

  20. The NEMO experiment at LNS A 5 km fiber optic link connects the NEMO test site in the port of Catania with the Laboratori Nazionali del Sud INFN Bidirectional optical link

  21. The Catania test site and Geostar ESONET The NEMO test site in Catania will also host GEOSTAR a deep sea station for on-line seismic and environmental monitoring by INGV. The NEMO test site will be the Italian site for ESONET (European Seafloor Observatory NETwork). Deployment: September 2004

  22. EU FP6 Design Study: KM3NET The experience and know how of the three collaborations is merging in the KM3-NET activity • Collaboration of 8 Countries, 34 Institutions • Aim to design a deep-sea km3-scale observatory for high energy neutrino astronomy and an associated platform for deep-sea science • Request for funding for 3 years Astroparticle Physics Physics Analysis System and Product Engineering Information Technology Shore and deep-sea structure Sea surface infrastructure WORK PACKAGES Risk Assessment Quality Assurance Resource Exploration Associated Science A Technical Design Report (including site selection) for a Cubic kilometre Detector in the Mediterranean Thompson

  23. Towards the Mediterranean km3 NEMO activities • Select an optimal site for the km3 installation • Submarine technology R&D • Construction: improve reliability, reduce costs • Deployment: define strategies taking profit of the • newest technological break-through • Connections: improve reliability, reduce costs • Electronics technology R&D • Readout: reduce power consuption • Transmission: increase bandwidth, reduce power consumption

  24. Towards the Mediterranean km3: Site selection • Depth • Lower atmospheric muon background • Water optical transparency • Large Cherenkov photons mean free path (absorption) • No change of photon direction (scattering) • Low biological activity • Low optical background (bioluminescence) • Low biofouling and sedimentation on Optical Modules • Low particulate density (light scattering) • Weak and stable deep sea currents • Reduced stresses on mechanical structures • Reduced stimulation of bioluminescent organisms • Distance from the shelf break and from canyons • Installation safety (turbidity avalanches) • Proximity to the coast and to existing infrastructures • Easy access for sea operations • Reduction of costs for installation and maintenance

  25. Candidate sites for the km3 APpEC Meeting, January 2003 ANTARES NESTOR NEMO 2400m 3400m 3800:4000 m

  26. Site selection: Expected atmospheric muon fluxes Bugaev BAIKAL ANTARES (Toulon) AMANDA (Antarctica) NEMO (Capo Passero) NESTOR (Pylos) Downgoing muon background is strongly reduced as a function of detector installation depth. Depth 3500 m (equivalent to Gran Sasso, Kamioka,..) is suggested for detector installation

  27. absorption a() • scattering b() • attenuation c() = a() + b() • effective scattering b()(1-<cos >) • Blue light (~440nm): • maximum transmission in water • peak of PMT Q.E. (bialkali) • Cherenkov emission region Water optical properties Smith & Backer large area PMT (8”:13”) La =1/a glass cutoff Blue light La ~70 m mu-metal shield Pressure resistant glass housing (17”)

  28. Capo Passero: Seasonal dependence of water optical properties temperature salinity c(440) a(440) pure seawater La= 66  5 m Data taken in August (3 profiles superimposed) km3 depths interval Indirect estimation of Lb 70 m March (4 profiles superimposed) May (2 profiles superimposed) December (2 profiles superimposed) Profiles as a function of depth of oceanographic and optical properties in Capo Passero • Seasonal dependence of oceanographical (Temperature and Salinity) and optical (absorption and attenuation) properties has been studied in Capo Passero • Variations are only observed in shallow water layers

  29. Seawater optical properties in Toulon and Capo Passero Optical properties have been measured in joint ANTARES-NEMO campaigns in Toulon and in Capo Passero (July-August 2002) • Absorption lengths measured in Capo Passero are close to the optically pure sea water data • Differences between Toulon and Capo Passero are observed for the blue light absorption NEMO data ANTARES data

  30. Capo Passero: Optical background Bioluminescent bacteria concentration 100 ml-1 10000 2002 data 1000 30 kHz Counting rate (kHz) 100 10 1 0 5 10 15 20 25 30 Time (mn) Optical data are consistent with biological measurements: No luminescent bacteria have been observed in Capo Passero below 2500 m Optical background was measured in Capo Passero with different devices. Data are consistent with 30 kHz background on 10” PMT at 0.3 spe (mainly 40K decay, very few bioluminescence). Schuller

  31. Capo Passero: Optical background long term measuremts 35 2.0% Spring 2003 data 30 kHz 30 1.5% Time above 200 kHz 25 1.0% Counting rates (kHz) 20 0.5% 15 0.0% 0 7 14 21 28 35 42 49 Days Measurements were carried out in different seasons showing the same optical background values. Schuller Schuller

  32. Toulon: Optical background measured by prototype line Baserate: median of rate in 15 min for 65 days Quiet phases: 60 kHz BurstFraction: fraction of time in 15 min in which rate is >1.2 x baserate

  33. Capo Passero site characteristics • Light absorption lengths (~70 m @440 nm) are compatible with optically pure sea water values. Measured values of optical properties are constant through the years (important: variations on La and Lc will directly change the detector effective area) • Optical background is low (consistent with 40K background with only rare occurrences of bioluminescence bursts) • The site location is good (close to the coast, flat seabed for hundreds km2, far from the shelf break and from canyons, far from important rivers) • Measured currents are low and regular (2-3 cm/s average; peak value<12 cm/s) • TheSedimentation rate is low (about 60 mg m-2 day-1) • No evidence of recent violent eventsfrom core analysis (last 60000 years ago)

  34. Towards the Mediterranean km3: architecture Design detector layout and study detector performances as a function of site parameters (depth, water properties,...) • The design of the Mediterranean km3 detector is addressed to fit physics requirements: • Effective area  1 km2 • Angular resolution close to intrinsic resolution • (  0.1° for muons produced by E10 TeV ) • Energy threshold of a few 100 GeV

  35. km3 architecture: homogeneous lattice or high local density ? 750 m height 780 m height Homogeneous detector (5600 PMTs): 400 strings arranged in 20x20 lattice 60 m between strings 60 m vertical distance between PMTs “Tower” detector (5832 PMTs): 81 towers arranged in 9x9 lattice 140 m between towers 20 m beam length 40 m vertical distance between beams

  36. The NEMO tower The NEMO tower is a semi-rigid 3D structure designed to allow easy deployment and recovery. High local PMT density is designed to perform local trigger. Height: compacted 15:20 m total 750 m instrumented 600 m n. beams 16 to 20 n. PMT 64 to 80 Beams: length 20m spacing 40 m

  37. km3 architecture: homogeneous lattice or high local density ? 750 m height 780 m height Homogeneous detector (5600 PMTs): 400 strings arranged in 20x20 lattice 60 m between strings 60 m vertical distance between PMTs “Tower” detector (5832 PMTs): 81 towers arranged in 9x9 lattice 140 m between towers 20 m beam length 40 m vertical distance between beams

  38. km3 architecture: effect of water properties 0 10 Homogeneous lattice detector 5600 PMTs 20 kHz Effective Area (km2) -1 10 NEMO Tower detector 5832 PMTs 20 kHz -2 NEMO Tower detector 5832 PMTs 60 kHz 10 NEMO Tower detector 5832 PMTs 120 kHz 0.8 0.6 Median (degrees) 0.4 0.2 2 3 4 5 6 Log E (GeV) 10  Effective areas and median angles for the two different detector architectures and different optical background rates Optical noise Simulations performed with the ANTARES simulation package

  39. km3 architecture: angular resolution of the “tower detector” Icecube Aeff / km2 Icecube cos  NEMO simulations: optical background 30 kHz, optical properties of Capo Passero 1  10 TeV 10  100 TeV 100  1000 TeV

  40. Towards the Mediterranean km3: technological challenges electro optical cable: construction and deployment Electronics Power Distribution Underwater connections Data transmission system Power transmission system Detector: design and construction deployment and recovery Acoustic positioning

  41. Towards the Mediterranean km3: technological challenges Recent break-through in submarine technology Large bandwidth optical fibre telecommunications (DWDM): ”all data to shore” under test in NEMO and ANTARES Low power consumption electronics under test in NEMO Acoustic positioning under test in ANTARES High reliability wet mateable connectors under test in ANTARES and in NEMO Deep sea ROV and AUV technology under test in NEMO and ANTARES

  42. km3 technological challenges: data transmission system • Data transmission goals • Transmit the full data rate with minimum threshold • Only signal digitization should be performed underwater • All triggering should be performed on shore • Reduce active components underwater • Assuming • An average rate of 50 kHz (40K background) on each OM • Signal sampling (8 bits) at 200 MHz • Signal length of 50 ns (true for 40K signals)  10 samples/signal 5 Mbits/s rate from each OM  25 Gbits/s for the whole telescope (5000 OM) Rate affordable with development and integration of available devices for telecommunication systems

  43. km3 technological challenges: data transmission system • Based on DWDM and Interleaver techniques • First Multiplation Stage (Tower base): • 16 Channels coming from the 16 tower floors. The channels are multiplexed in one fibre at the base of each tower. • Second multiplation stage (secondary JB): • 32 channels coming from a couple of tower are multiplexed with an interleaver; • The output is a single fibre for each of the four couples of towers. All the fibres coming from the secondary JB go directly to shore (connection to the main electro-optical cable inside the main JB) A1 A2 A3 A4 E1 E2 E3 E4 B1 F1 B2 F2 B3 F3 B4 F4 1 2 3 4 C1 G1 C2 G2 C3 G3 C4 G4 D1 H1 D2 H2 D3 H3 D4 H4 A5 A6 A7 A8 E5 E6 E7 E8 B5 F5 B6 F6 B7 F7 B8 F8 5 6 7 8 C5 G5 C6 G6 C7 G7 C8 G8 D5 H5 D6 H6 D7 7H D8 H8 Primary JB Secondary JB Tower Possible architecture for the km3 detector Mostly passive componentsVery low power consumption

  44. km3 technological challenges: data transmission system STM1 flux, 155 MB per channel 200 GHz 100 GHz 100 GHz 100 GHz 100 GHz 1 A1 … 200 GHz 16 200 GHz 200/100 1.. 32 17 Secondary JB B1 … 200 GHz 32 200 GHz 33 C1 … 200 GHz 48 200 GHz 200/100 33.. 64 49 D1 … 200 GHz 64 200 GHz 65 E1 … 200 GHz 1.. 128 80 200 GHz 200/100 81 65.. 96 F1 … 200 GHz 96 200 GHz 97 G1 … 200 GHz 112 200 GHz 200/100 113 97.. 128 H1 … 200 GHz 128 Tower base Interleaver

  45. km3 technological challenges: low power electronics LIRA’s PLL Shielded PLL Stand Alone 200 MHz Slave Clock Generator T&SPC LIRAX2 200 MHz Write 10 MHz Read • Sampling Freqency: 200MHz • Trigger level remote controlled • Max Power dissipation <200 mW • Input dynamic range 10 bit • Dead time < 0.1% • Time resolution < 1 ns New full custom VLSI ASIC Presently under final laboratory testing Will be tested in some optical modules in NEMO Power Budget: ANTARES 900 PMTs: 16kW over 40km NEMO 5000 PMTs: 30kW over 100km

  46. km3 technological challenges: underwater connections The tower connections will be performed in air during the tower assembling. Some connections (link of the tower with the Junction Box) must be performed underwater ROV operated connection ANTARES connection Well tested technology - Solution adopted in Antares and NEMO Expensive: connections must be minimized

  47. km3 technological challenges: the NEMO junction box An alternative method to build high pressure vessel Cavity to fill with oil • Using this method of construction for the vessels it is possible to decouple the two problems of: • resistance to pressure • resistance to corrosion • Moreover it is possible to use an electrical transformer designed to be employed under pressure. In this way the dimensions of the pressurized vessel and its cost can be reduced. Composite (GRP) Steel

  48. km3 technological challenges: ROV / AUV A1 A2 A3 A4 E1 E2 E3 E4 AUV B1 F1 B2 F2 B3 F3 B4 F4 ROV 1 2 3 4 C1 G1 C2 G2 C3 G3 C4 G4 D1 H1 D2 H2 D3 H3 D4 H4 A5 A6 A7 A8 E5 E6 E7 E8 B5 F5 B6 F6 B7 F7 B8 F8 5 6 7 8 C5 G5 C6 G6 C7 G7 C8 G8 D5 H5 D6 H6 D7 7H D8 H8 AUV Docking station The ROV deep sea technology (under test in ANTARES) is well established but implies operativity limitations due to ROV-carrier ships costs and availability. Operativity are also dependent on sea state. ROV is bounded to the ship through umbilical cables  Difficult movimentation in a sumbarine jungle of strings/towers

  49. Summary I The forthcoming km3 neutrino telescopesare “discovery” detectors with high potential to solve HE astrophysics basic questions: UHECR sources HE hadronic mechanisms Dark matter ... The underice km3 ICECUBE is under way, following the AMANDA experience The Mediterranean km3 neutrino telescope, when optimized, will be an powerful astronomical observatory thanks to its excellent angular resolution

  50. Summary II The feasiblity of km3 detectors at depth  3500 m is widely accepted The undersea technology for the km3 is under test and development by three collaborations: ANTARES NEMO NESTOR A proposal for a 3 years design study of the km3 has been submitted to EU under the KM3-NET The answer is pending but good reasons to be confident

More Related