1. Status of the ANTARES Neutrino-Telescope Alexander Kappes Physics Institute University Erlangen-Nuremberg for the ANTARES Collaboration WIN´05, 6.–11. June 2005 Delphi, Greece  Introduction  The ANTARES Detector  First Results from Test-Lines  Outlook

2. 6. - 11. June 2005 WIN´05 Delphi, Greece2 Alexander Kappes University Erlangen-Nuremberg Active Galactic Nuclei Supernova Remnant (RX J1713.7-3946) Gamma Ray Burst Cosmic accelerators (Bepposax) Hubble H.E.S.S.

3. 6. - 11. June 2005 WIN´05 Delphi, Greece3 Alexander Kappes University Erlangen-Nuremberg Detection of Cosmic Neutrinos  A !  X Earth used as shield against all other particles Čerenkov light: Čerenkov angle: 42 o wave lengths used: 350 – 500 nm low cross section requires large detector volumes key reaction:  + A !  + X Detector deployed in deep water / ice to reduce downgoing atmospheric muons

4. 6. - 11. June 2005 WIN´05 Delphi, Greece4 Alexander Kappes University Erlangen-Nuremberg Physics with Neutrino Telescopes Searching for point-like neutrino sources Measurement of diffuse neutrino flux Search for Dark Matter (WIMPs) Search for exotic particles: e.g. magnetic monopoles

5. 6. - 11. June 2005 WIN´05 Delphi, Greece5 Alexander Kappes University Erlangen-Nuremberg Why a Neutrino Telescope in the Mediterranean Sea? Sky coverage complementary to telescopes at South Pole Allows to observe the region of the Galactic Centre Not seen Mkn 501 Mkn 421 Crab SS433 Mkn 501 GX339-4 SS433 Crab VELA GalacticCenter Not seen South Pole Mediterranean Sea Sources of VHE  emission (HESS 2005)

6. 6. - 11. June 2005 WIN´05 Delphi, Greece6 Alexander Kappes University Erlangen-Nuremberg The ANTARES Collaboration 20 institutions from 6 European countries

7. 6. - 11. June 2005 WIN´05 Delphi, Greece7 Alexander Kappes University Erlangen-Nuremberg The ANTARES Detector 460 m 70 m 14.5 m String Optical Module Junction Box Buoy Submersible Cable to Shore station artist´s view (not to scale) Hostile environment:  pressure up to 240 bar  sea water (corrosion)

8. 6. - 11. June 2005 WIN´05 Delphi, Greece8 Alexander Kappes University Erlangen-Nuremberg One of 12 ANTARES Strings Buoy  keeps string vertical (horizontal displacement < 20 m) Storey  3 optical modules (45 o downwards)  electronics in titanium cylinder EMC cable  copper wires + glass fibres  mechanical connection between storeys Anchor  connector for cable to junction box  control electronics for string  dead weight  acoustic release mechanism

9. 6. - 11. June 2005 WIN´05 Delphi, Greece9 Alexander Kappes University Erlangen-Nuremberg Optical Module Glass spheres:  material: borosilicate glass (free of 40 K)  diameter: 43 cm; 1.5 cm thick  qualified for pressures up to 650 bar B-screening optical module Photomultipliers (PMT):  Ø 10 inch (Hamamatsu)  transfer time spread (TTS) = 1.3 ns  quantum efficiency: > 20% @ 1760 V (360 < < 460 nm)

10. 6. - 11. June 2005 WIN´05 Delphi, Greece10 Alexander Kappes University Erlangen-Nuremberg DAQ and Online Trigger Data acquisition:  signals digitized in situ (either wave-form or single photo-electron (SPE))  all data above low threshold (0.3 SPE) sent to shore  no hardware trigger Online trigger:  computer farm at shore station (~100 PCs)  data rate from detector ~1GB/s (dominated by background)  trigger criteria: hit amplitudes, local coincidences, causality of hits  trigger output ~1MB/s = 30 TB/year Computer Centre Control room

11. 6. - 11. June 2005 WIN´05 Delphi, Greece11 Alexander Kappes University Erlangen-Nuremberg Online Trigger Level 1: coincidences at one storey (  t 2.4 SPE) Level 2: causality condition  t < n / c ·  x Level 3: accept if sufficiently many causally related hits exist Efficiency cos  C = 1 / n Advanced algorithms under development

12. 6. - 11. June 2005 WIN´05 Delphi, Greece12 Alexander Kappes University Erlangen-Nuremberg Calibration devices (Overview) Time calibration system  1 LED in each optical module  Optical beacons - LED beacons at 4 different storeys - Laser beacon at anchor Acoustic positioning  receivers (hydrophones) at 5 storeys  1 transceiver at anchor  autonomous transceivers on sea floor Tiltmeter and compass at each storey

13. 6. - 11. June 2005 WIN´05 Delphi, Greece13 Alexander Kappes University Erlangen-Nuremberg Time-Calibration Systems timing resolution of PMT signals determines pointing accuracy limited by intrinsic TTS of PMTs (1.3 ns) ) resolution of time calibration has to be better than 0.5 ns expected variations of individual time offsets of PMT signals ~10 ns complete calibration performed prior to deployment two independent in situ calibration systems for PMTs available: Flashed LEDs in optical modules:  blue LED attached to back of each PMT  illuminates only local PMT Flashed optical beacons:  illuminate mainly PMTs on neighbouring strings  each beacon contains PMT for recording of emission time OM PMT

14. 6. - 11. June 2005 WIN´05 Delphi, Greece14 Alexander Kappes University Erlangen-Nuremberg Positioning System motion of lines due to sea current (up to 30 cm/s) 0.5 ns timing resolution requires 10 cm position accuracy for each PMT Tiltmeters and compasses: resolutions: tiltmeters = 0.2 o, compasses = 1 o Acoustic system: transmitter frequencies: 8–16 kHz(long distance) 40–60 kHz (short distance) distance measurements via run time of acoustic signals reconstruction of storey positions via triangulation System designed to provide PMT position accuracy better than 10 cm.

15. 6. - 11. June 2005 WIN´05 Delphi, Greece15 Alexander Kappes University Erlangen-Nuremberg Environmental Parameters Continuously measured with various instruments on a dedicated string (Instrumentation Line) or at string anchors quantities directly influencing reconstruction  attenuation length (25–60 m, depending on wave length and time) resolution ¼ 4 m  sound velocity ) acoustic positioning system resolution = 0.1 m/s other quantities measured  direction/speed of water current (via Doppler effect) precision:  v = 0.5 cm/s,  = 0.5 o  temperature, salinity (via conductivity)  water pressure (device attached to anchor)

16. 6. - 11. June 2005 WIN´05 Delphi, Greece16 Alexander Kappes University Erlangen-Nuremberg Angular resolution (simulation)  E < 10 TeV: dominated by kinematics (Æ[,   E > 10 TeV: dominated by  reconstruction accuracy Muon Reconstruction Energy resolution (simulation)  low E: muon track length  E > 1 TeV: Čerenkov light from radiative losses (small elm. showers)  10 TeV)  (log E) ¼ 0.3 (E > 1 TeV) Muon momentum

17. 6. - 11. June 2005 WIN´05 Delphi, Greece17 Alexander Kappes University Erlangen-Nuremberg Detector Infrastructure and Prototype Lines Deep-sea cable to shore station deployed Junction box deployed and connected to deep-sea cable Prototype lines deployed, connected to junction box and successfully recovered after 5 months

18. 6. - 11. June 2005 WIN´05 Delphi, Greece18 Alexander Kappes University Erlangen-Nuremberg Results from Prototype Lines (2003) Long term measurements of optical background in the deep sea: 0.4 seconds 3.5 months Baseline rate Technical problems: damaged optical fibre inside cable + water leak in electronics container ) no data with ns time resolution + loss of a storey

19. 6. - 11. June 2005 WIN´05 Delphi, Greece19 Alexander Kappes University Erlangen-Nuremberg New Test-Lines: MILOM and Line0 Deployed March 2005, connected April 2005 MILOM: Mini Instrumentation Line with Optical Modules Line0: full line without electronics (test of mechanical structure)

20. 6. - 11. June 2005 WIN´05 Delphi, Greece20 Alexander Kappes University Erlangen-Nuremberg MILOM setup Optical components: equipped with final electronics 3+1 optical modules at two storeys timing calibration system:  two LED beacons at two storeys  Laser Beacon attached to anchor acoustic positioning system:  receiver at 1 storey  transceiver (transmitter + receiver) at anchor allows to test all aspects of optical line Instrumentation components: current profiler (ADCP) sound velocimeter water properties (CSTAR, CT)

21. 6. - 11. June 2005 WIN´05 Delphi, Greece21 Alexander Kappes University Erlangen-Nuremberg First results from MILOM Timing calibration with LED beacons: Measured relative offset of 3 optical modules on same storey Large light pulses used ) TTS of PMT small Optical beacon signal Time (ns) Amplitude Time difference between optical modules electronics contribution to resolution around 0.5 ns investigations in progress to separate various contributions  t OM1 – OM0  t OM2 – OM0  =0.75ns  =0.68ns beacon signal

22. 6. - 11. June 2005 WIN´05 Delphi, Greece22 Alexander Kappes University Erlangen-Nuremberg First results from MILOM Acoustic positioning: Several acoustic transponders installed Currently only results from 1D measurements available Systematic effects under control on the level of 2 mm. Time (day) 2 4 6 8 10 12 14 16 18 20 96.58 96.59 96.60 96.61 Distance (m) distance from transponder (anchor) to receiver (first storey) vs. time distribution around daily average 8 6 4 2 0 2 4 6 8 Distance (mm)

23. 6. - 11. June 2005 WIN´05 Delphi, Greece23 Alexander Kappes University Erlangen-Nuremberg First Results from MILOM Compass headings from all three MILOM storeys: mostly synchronous movement of all storeys

24. 6. - 11. June 2005 WIN´05 Delphi, Greece24 Alexander Kappes University Erlangen-Nuremberg First results from MILOM Environmental data: Water temperature + sound velocity Temperature almost constant at 13.2 o C Water temperature determines sound velocity (at given depth) Water temperature Sound velocity Velocity (m/s)

25. 6. - 11. June 2005 WIN´05 Delphi, Greece25 Alexander Kappes University Erlangen-Nuremberg First results from MILOM Environmental data: Sea current (current profiler) Most times sea current < 15 cm/s Significant changes of direction over periods from hours to days

26. 6. - 11. June 2005 WIN´05 Delphi, Greece26 Alexander Kappes University Erlangen-Nuremberg First results from MILOM MILOM is a big success: Data readout (waveforms + SPE) is working as expected and yields ns timing information In situ timing calibration and acoustic positioning reach expected resolution All environmental sensors are working well Continuous data from Slow Control (monitoring of various detector components) Lots of environmental and PMT data available; intensive studies ongoing

27. 6. - 11. June 2005 WIN´05 Delphi, Greece27 Alexander Kappes University Erlangen-Nuremberg Line0 deployed to test mechanical structure equipped with autonomous recording devices  water leak sensors  sensors connected to electrical and fibre loops for attenuation measurements recovered in May 2005 Results: no water leaks occurred optical transmission losses at various points on fibres evidently all losses occur inside electronics container at entry and exit from cylinder presently under intense investigations On first prototype strings fibres inside cables were damaged

28. 6. - 11. June 2005 WIN´05 Delphi, Greece28 Alexander Kappes University Erlangen-Nuremberg ANTARES: further schedule First full string (Line1) to be deployed and connected end of 2005 Full detector installed in 2007 From 2006 on: physics analysis !

29. 6. - 11. June 2005 WIN´05 Delphi, Greece29 Alexander Kappes University Erlangen-Nuremberg The future: KM3NeT common effort of European telescope groups (ANTARES, NEMO, NESTOR) + associated sciences aim: build and operate a km 3 neutrino telescope in the Mediterranean Sea complementary to IceCube at the South Pole expect to get EU funding (10 MEuro) for a design study (total budget 24 MEuro) by beginning of 2006 Technical Design Report early 2009 km 3 detectors required to exploit full physics potential of neutrino telescopes

30. 6. - 11. June 2005 WIN´05 Delphi, Greece30 Alexander Kappes University Erlangen-Nuremberg Conclusions MILOM proved to be a big success  data readout is working as expected  in situ timing and position resolution sufficient to reach angular resolution 10 TeV  many more data to analyse Line0 results  mechanical structure water tight and pressure resistant  optical losses in fibres currently under intense investigation First full string expected to be deployed this year; Full detector in 2007 Well prepared for physics data to come in 2006