1. Status of the Baikal Neutrino Telescope NT200+ VLVNT2 Workshop, Catania, 9.11.2005 Ralf Wischnewski DESY, Zeuthen Outline: - Motivation / Methods - The new Detector NT200+ : Design + First Light - Why NT200+ ? - Diffuse cosmic neutrino searches with NT200 - Sensitivity of NT200+ : diffuse cosmic neutrinos. Other physics results from NT200  See talk by Z.Djilkibaev on Friday (Monopoles, WIMPs, HE muons, prompt leptons,..) - Future: A km3 “Gigaton Volume Detector” at Baikal.

2. R.Wischnewski VLVNT2 Workshop, Catania, 9.11.2005 2 High Energy -Astronomy --> Catch first astrophyical HE ’ s  Cosmic ray acceleration sites  New observational window to Universe (new objects ?) Dark Matter (neutralino annihilation in Earth/Sun/Gal.C.) Prompt lepton production in atmosphere ( + µ ; cross sections, …) Exotic particles: Magnetic Monopoles (relativistic or ultra-slow) … CR: HE atmospheric muons (exotic component ?), composition… Neutrino Telescopes: Physics Motivation Astro - Astro - - Particle Physics

3. R.Wischnewski VLVNT2 Workshop, Catania, 9.11.2005 3 HE Neutrino Detection: “Muons” and “Cascades” O(km) long muon tracks direction determination by Cherenkov light timing  5-15 m - Good directionality by Cherenkov timing - Poor energy resolution Charged Current (CC)  Electromagnetic & hadronic cascades ~ 5 m - Good energy resolution - Bad pointing CC e  + Neutral Current

4. R.Wischnewski VLVNT2 Workshop, Catania, 9.11.2005 4 Baikal Baikal Collaboration: Russia – Germany - Institute of Nuclear Research, Moscow - Moscow State University - DESY Zeuthen - Irkutsk State University - Nishni Novgorod State Techn. Univ. - State Marine Techn. Univ. St.Petersburg - Kurchatov Institute, Moscow - JINR, Dubna ~45 authors Project Milestones: >1983: site / water studies; R&D: large area PMT, underwater techno., physics small setups (exotics search) 1991: Project NT200 approved 1993: NT36 – Telescope the first underwater array operates...first  ’s and ’s in NeutrinoTelescope 1998: NT200 commissioned 2005: NT200+ commissioned

5. R.Wischnewski VLVNT2 Workshop, Catania, 9.11.2005 5 4km OffShore Depth: 1366 m Shore Station

6. R.Wischnewski VLVNT2 Workshop, Catania, 9.11.2005 6 ExtString 1 ExtString 3 ExtString 2 NT200 Central+Outer Str. New ShoreCable 100 m Foto from March, 2005, 4km off-shore: NT200+ deployment from 1m thick ice. Ice – A perfect natural deployment platform Ice is stable for 6-8 winter-weeks/year : –Upgrades & maintenance –Test & installation of new equipment –Operation of surface detectors (EAS, acoustics,… ) –Electrical winches used for deployment operations (all connections done dry)

7. R.Wischnewski VLVNT2 Workshop, Catania, 9.11.2005 7 NT200 running since 1998 - - 8 strings with 192 optical modules - - 72m height, R=20m, 1070m depth, V geo =0.1Mton - -  effective area: >2000 m 2 (E  >1 TeV) - - Shower Eff Volume: ~1 Mton at 1 PeV NT200+ commissioned April 9, 2005 - 3 new strings, 200 m height, 36 OMs - - 1 new bright Laser for time calibration imitation of 10 PeV-500 PeV cascades, >10^13 photons/pulse w/ diffusor,  SNO-Calib - 2 new 4km cables to shore - - DAQ – New Underwater & Shore Station: Underwater Linux embedded PCs, Industrial Ethernet Systems 4 Km to shore NT200+ is tailored to UHE n-induced cascades - 5 Mton equipped volume - V_eff >10 Mton at 10 PeV  4fold sensitivity gain with only 20% additional PMTS. The Baikal Detector NT200+

8. R.Wischnewski VLVNT2 Workshop, Catania, 9.11.2005 8 4 Km to shore DAQ and Slow Control of NT200+ DAQ Modernization (2004/05): - First PCs/PC104 used underwater; - DSL Mbps to shore (w/ spare); - - UW-ethernet (hot spares); - - Full multiplexing of all data/control streams; - - Industrial auxiliary components (EthRelais,...) - - Linux (uw + shore) UW-PCs and other Central DAQ-Spheres UW-PCs design NT200+ DAQ/SlowControl schematcis

9. R.Wischnewski VLVNT2 Workshop, Catania, 9.11.2005 9 Laser intensity ~ 10 12 – 5 10 13  /pulse E_Shower ~ 10 – 500 PeV - Ch.13 – 187 m away from Laser - - Time Jitter = Light Scattering + Electronics First light on NT200+: Laser pulses as high-energy cascades FWHM ~10ns @2pe,190m !

10. R.Wischnewski VLVNT2 Workshop, Catania, 9.11.2005 10 t1t1t1t1 t2t2t2t2 t 12 5 series of Laser pulses NT200+ time resolution  t = t 1 + t 12 – t 2  t 1,  t 2 - PMT jitter and light scattering  t 12 )  2 ns - electronics jitter Light scattering - scattering length 30 m - distance to Laser ~200 m Jitter of electonics ~2 ns Jitter of electonics ~2 ns - synchro cable length 1.2 km - TDC bin 2 ns The amplitude dependence of relative time jitter measured for several pairs of channels of NT200 and external strings. Red line is result of Scat_MC calculation.

11. R.Wischnewski VLVNT2 Workshop, Catania, 9.11.2005 11 Laser intensity reconstruction  r < 1 m  I/I ~ 6% lowest intensity five laser intensities NT200+: “Laser-cascade” reconstruction NT200 NT200+ 3 outer str. Reconstruct z-r Laser vertex reconstruction

12. R.Wischnewski VLVNT2 Workshop, Catania, 9.11.2005 12 Why NT200+ ? Diffuse Cosmic Neutrino Search with NT200.

13. R.Wischnewski VLVNT2 Workshop, Catania, 9.11.2005 13 NT200: Search for High Energy Diffuse Cascades Watch the non-instrumented volume below detector for cascades = Upward moving light fronts.  („BG“) large effective volume NT200 V geo (NT-200) 10 Mton Effective Volume vs. Energy NT200+ : Instrument the volume below detector  better BG suppression and improved physics.

14. R.Wischnewski VLVNT2 Workshop, Catania, 9.11.2005 14 Limits for diffuse cosmic neutrino fluxes 1:1:1 flavor flux ratio @earth limits given for all-flavors (  e + e +  +  +  +  ) Baikal + Amanda 1 : B10, 97, ↑μ 2 : A-II, 2000, unfold. 3 : A-II, 2000, cascade 4 : B10, 97, UHE 5 : NT200, 98-02, cascade 6: A-II, 2000, UHE sens. 7: A-II, 2000-03 ↑μ sens. 8: IceCube 3 years 9: NT200+, 3yr, casc sens. 6 7 8 9 Baikal Cascades (98-02) subm. APP

15. R.Wischnewski VLVNT2 Workshop, Catania, 9.11.2005 15 Expectation for NT200+ ‘s Predicted all-flavor-sensitivity for astrophysical ‘s : E 2 Ф < 2.7 · 10 -7 GeV cm -2 s -1 sr -1 (3 years) ~ A-II / 4yr mu  3-4 fold improvement over NT200. Much improved reconstruction of cascade coordinates + energy NT200 NT200 NT200+ NT200+ Is a conservative predicition: vertex + energy reconstruction will improve sensitivity ! e 15Mton 30Mton

16. R.Wischnewski VLVNT2 Workshop, Catania, 9.11.2005 16 Future: A Gigaton Volume (km3) Detector at Baikal

17. R.Wischnewski VLVNT2 Workshop, Catania, 9.11.2005 17 NT200 + - important step towards a km3 @ Baikal NT200+ as a subunit of a km3 scale detector. For High Energy Cascades: A single small string replacing the NT200 central core reduces V eff less than x3 for E>100TeV.  A short string instead of NT200 as a subunit for a Gton scale detector is ok ! 140 m Effective volume for simplified NT200’s. e

18. R.Wischnewski VLVNT2 Workshop, Catania, 9.11.2005 18 Sparse instrumentation: 91 strings with 12/16 OM = 1308 OMs  Casacde effective volume for 100 TeV: ~ 0.5 -1.0 km³   Muon threshold between 10 and 100 TeV Baseline schedule: - R&D +TechDesRep 2006-08. Funded. - - Construction ≥2009. A Gigaton (km3) Detector in Lake Baikal Mini NT200+

19. R.Wischnewski VLVNT2 Workshop, Catania, 9.11.2005 19 - Basic detector element is NT200+. Under “Real Physics Test“ since 4/2005. - -Dedicated R&D for Baikal/km3 – technology starts in 2006. Redesign of some key elements is under consideration. Issues: - - Optical Module: Quasar vs other? Grouping 2 vs 3? FADC readout?... - - Time synchronization: electrical vs. optical,.... - - System architecture: subarray trigger, string controller, data transfer,... - - Auxiliary systems: acoustic positioning, bright laser sources, … - - MC design optimization - -... - - Interaction Baikal/km3  KM3NeT : Common activities for a few selected technical issues - could this be useful ? e.g. OMs (design/in-situ tests@NT200+); MC (design; verification); TimeSync.; Auxil.Dev.; …,... A Gigaton (km3) Detector in Lake Baikal - Status -

20. R.Wischnewski VLVNT2 Workshop, Catania, 9.11.2005 20 The Baikal Telescope is successfully running since >10 years.NT200 - High Sensitivity in HE-diffuse search (cascades): “Mton-detector” - Number of relevant other results: Magnetic Monopoles, WIMPs, GRB, atm.  NT200+ - Natural upgrade after diffuse NT200–success story: New 5 Mton instrumented detector commissioned in April, 2005. - Tailored to diffuse cosmic nu’s: >10Mton at 10PeV. Diffuse sensitivity: E 2 Ф  < 0.9 ·10 -7 GeV cm -2 s -1 sr -1 (3yr NT200+) - Shower analysis improvement: vertex, energy + direction. - UHE cosmic  and transient sources: sensitivities under study. Future: Gigaton Volume Detector (km3) in Baikal. - NT200+ serves as realistic test object. Technical Proposal within 3 yrs. Summary see talk on physics by Z.Djilkibaev