The sources of cosmic neutrinos The scientific exploitation of the KM3NeT detector

Transcription

1 The sources of cosmic neutrinos The scientific exploitation of the KM3NeT detector And Status of KM3NeT at Nikhef A.J. Heijboer, A.M. van den Berg, R. Bruijn, M. de Jong (spokesperson), P. Kooijman, D. Samtleben. 1

2 Cosmic neutrinos have been discovered! But origin/sources unknown IceCube Collaboration, Science 342, (November 2013) Observable from Mediterranean with upgoing neutrinos. Most events have >10 deg resolution Upgoing in IceCube Galactic center Point source likelihood ratio 28 very high energy events (12 expected from background) : 4.3 discovery Major boost to interest in neutrino astronomy. The flux is large and extends to very high energy Signal just begs for a large Northern Hemisphere detector KM3NeT. 2

3 Cosmic neutrinos have been discovered! But origin/sources unknown IceCube Collaboration, Science 342, Galactic center Limit on neutrino flux (GeV-1 cm-2 s-1) Is this a point source (arxiv )? Antares says : no Observable from Mediterranean with upgoing neutrinos. Most events have Nb: Antares can use >10 deg resolution upgoing here Flux required to produce IC 'hotspot' Galactic center ArXiv: ; accepted by ApJ Point source likelihood ratio ArXiv: ; accepted by ApJ 28 very high energy events (12 expected from background) : 4.3 discovery Major boost to interest in neutrino astronomy. The flux is large and extends to very high energy Signal just begs for a large Northern Hemisphere detector KM3NeT. 3

4 Why KM3NeT has the future Location, Medium, Technology KM3NeT resolution SNR RXJ 1713 IC IC Medium: Clear water resolving power Antares already has better resolution than IceCube: - Antares (12 strings): 0.4o, - IceCube 80 strings : 0.5o, IceCube 22 strings: 1.3o - KM3NeT: ~0.1o Location: Excellent view of the Galaxy From Mediterranean, the Galaxy can be studied in the full energy range (At highest energies neutrino telescopes are omnidirectional) Technology: Multi-PMT design offers many advantages over single-pmt, including large cost saving. Future of photo-detection? (ORCA, Chips, IceCube upgrades?) KM3NeT string IceCube string* : 0.3 M : 1 M$+ *IC and KM3NeT strings have ~same photosensor area 4

5 Phased KM3NeT implementation 12 strings <2016 running since '08 Leading search for galactic sources Phase 1 30 strings 2015 funded >3x Antares, confirm IC signal? Phase strings 2018 need 60M Study cosmic neutrinos in detail. (see later) Phase strings M } Scope of program Antares Discover galactic Supernova remnants IceCube discovery is a game-changer. Large flux, up to very high energies KM3NeT can do more interesting science with less strings. Phase 1.5 : one or two building blocks (of 115 strings) to follow-up on IC discovery Aim is to acquire international investment funds for this on short timescale. 5

6 Phased KM3NeT implementation 12 strings <2016 running since '08 Phase dramatically fundedthe scientific thestrings TeV-PeV range have strengthened Phase 1.5 justification to build KM3NeT... KM3NeT will have the unique opportunity to study sources in the central parts of our Galaxy, thanks to its different field of view M compared strings to IceCube, to its larger size, andneed to its better angular (seeto later) Resolution... We urge the KM3NeT community work with high priority towards Phase-1.5. Phase 2 letter of the KM3NeT Scientific and Technical Advisory 700 strings M The recent findings by IceCube of extra-terrestrial neutrinos in Committee (STAC) to the Chair of ESFRI. Leading search for galactic sources >3x Antares, confirm IC signal? Study cosmic neutrinos in detail. } Scope of program Antares Discover galactic Supernova remnants IceCube discovery is a game-changer. Large flux, up to very high energies KM3NeT can do more interesting science with less strings. Phase 1.5 : one or two building blocks to follow-up on IC discovery Aim is to acquire international investment funds for this on short timescale. 6

7 KM3NeT to study cosmic neutrino flux. - Task force set up to study science potential of Phase Initial results look promising - Expect complete picture by June (Neutrino2014 conference +LoI) PeV e Antares limit icecube flux 3 sigma, 230 strings Additional channels (electron, tau neutrinos) being pursued Initial estimates: 18 signal over 16 bg events in 1 yr (=4 sigma) ~1 degree resolution should be achievable Upgoing muon analysis: can confirm the signal with a 1-2 years of data These Events will have 0.1 degree resolution! pin down the sources 7

8 Our role in KM3NeT String deployment (with Nioz) penetrator Cable & Optical data transport. PMT support (3-d printed) Cooling structure collar fan out board (KVI) firmware PMT base +ASICs The Netherlands is not just participating: We are driving KM3NeT. Hence this FOM program and continues support from Nikhef is crucial not just for the NL contribution but for the whole of KM3NeT. Light Collector (KVI) 8

9 Prototype Optical Module Final integration tests in dedicated dark box Connected to Antares Instrumentation Line for > 1 year now. 9

10 Prototype Optical Module - results Atm. muons K40 bioluminescence data Rate [Hz] preliminary Rate [a.u.] Publication in preparation >6 DOMs within 20ns signal dominated by atmospheric muons Upper PMTs more events directional information from single floor! enormously rich data from single OM. NL Analysis 10

11 Next: Prototype Detection Line 3 DOMs assembled at Nikhef + Erlangen DOMs Tested (red box) at Nikhef Penetrators, Veoc + string assembly at Nikhef. Left nikhef 3 weeks ago Tested/calibrated at CPPM, Marseille To be deployed near Sicily beginning of May 11

12 Status of KM3NeT Collaboration since institutes, 180 physicists, NL spokesperson MOU drafted Review boards (science+technology & resources) Wafer with Coco ASICS PMT base (Nov 2013) Working on construction of 'phase-1' 30 Strings in Fr and It. timescales driven by constraints on currently available Fr+It funding. R&D phase coming to an end now/soon Prototype optical module in the sea for >1 year still works. Prototype detection unit (string) to be deployed soon Final mechanics+deployment test beginning of June Phase-1 Production phase starting (120 DOMs and 1 String by end 2014) 600 PMTs for first string delivered end 2013, bases ready. PMT tender (15k units) awarded to Hamamatsu by It. Electronics ~ready for mass production, e.g: Tender for base production published, ASICs for bases delivered (Nikhef) Signal collection boards ordered (KVI) 12

13 Nikhef Prototype detection unit has left Nikhef workshop: ~done. Preparing for mechanics & deployment test (June) Penetrator production has had problems (leaks): looks healthy now! 4 VEOCs being produced in industry (2 for test, Line 1 + spare) Booked boat trip with NIOZ Includes knowledge transfer to CPPM Optical Networks being finalized Test-setups + detailed simulations CLB firmware (White Rabbit) going well Base production Tender published Next step: production of Optical Modules Goal for 2014 is 40 Nikhef + 80 DOMs at 2 other integration sites Setting up production plan VEOC cable (in industry, tender) String mechanics 13

14 Nikhef KM3NeT group 5 staff FTE +2 part-time (= enormous help) 4 students (2 finishing on Antares, 1 KM3NeT, 1 ORCA) 1 postdoc leaving ~now large amount of technical manpower from Nikhef. Have had a leading role in Antares data analysis (point source searches, first GRB analysis) effort ramping down now (=ok) KM3NeT sensitivity studies : leadership role, but lack manpower (= not ok) Strengthening ties with Leiden University (D. Samtleben tenure track position). Leiden may join Nikhef consortium. Collaboration with Groningen/KVI is continuing: signal collection board production, Ad van den Berg (KVI) co-applicant of FOM proposal 14

15 The proposed FOM program Timeliness: Recent groundbreaking discovery.. Commissioning of Phase-1 starts in 2015; Need fast results to support next Phase. Build on existing expertise (previous FOM prog and Vidi grant Heijboer, ending ~now) Program would start 2015: after construction of Line-1 Focus: request junior scientists, no investment. 3 closely related research lines together perform core neutrino telescope science program Breadth: Build/maintain collaboration across: Universities of Leiden, Amsterdam, Groningen (KVI-Cart), Nikhef, Nioz* Long timeline: Commissioning and first science results (2015) Optimization and preparation of next phase (1.5) Next phase: start science run in 2018; 3 years of data. Possible concern: Phase 1.5 not guaranteed to happen (see next slide) * continued close collaboration on technical aspects, but sea science not part of the proposal. 15

16 Future investment funding (for Phase 1.5) Will require commissioning and performance demonstration of Phase-1. Prospects are better than ever: Discovery of cosmic neutrinos! means we need less investment to do more exciting science! Prototypes working very well (and clearly showing multi-pmt detection power) Recognition: Dutch roadmap for large scale infrastructures (last review: excellent + some very good ), CAN strategy report, ApPEC magnificent 7, Global neutrino network, SAF focusnotitie, CERN recognized experiment, NL planned to host ERIC headquarters, invited to Neutrino2014 conference, fit in top sector subtopic 'advanced instrumentation'. ESFRI: KM3NeT's response to recommendations of expert assessment group very positively received: remain on ESFRI roadmap for the foreseeable future. Strong support for next Phase by external expert scientists (STAC) and funding agencies (as represented in KM3NeT by the RRB). several strings must be successfully deployed and connected to the deep-sea infrastructure in order to demonstrate proper operation. Once achieved, the RRB will vigorously start the process to collect the required funding for KM3NeT-phase1.5. Opportunities to use technology elsewhere: Chips, Orca, IC, Hisparc, CTA letter of the Resources Review Board, RRB, (which represents the funding agencies) to the Chair of ESFRI. 16

17 Conclusions Cosmic neutrinos are there! We believe KM3NeT will be the ideal tool to study them: location, medium & (cost of) technology Phase 1.5 KM3NeT Phase-1 : Prototype-phase ending soon (PPM-DOM very successful) Next step: produce a significant fraction of DOMs and first line by the end of the year. (very tight, but not impossible) The Netherlands' stakes are high: We are not just participating, but a main player in the KM3NeT effort: Design concepts, Technology, Leadership (spokesperson). Significant investment (8.8 M, roadmap) needs science counterpart. With a FOM Program, we will achieve a leading role also in the scientific capitalization (like we have in Antares) Prospects for (international) investments for next phase are better. Need a science program at Nikhef, Leiden, KVI to fulfill these. Requested funds are 'modest': aimed at the core of neutrino telescope science program (no frills) : Write the main publications and demonstrate detector performance in the process (like we did in Antares). Discover the sources of cosmic neutrinos. 17

18 Thank you BACKUP 18

19 Backup: Sites Strong case for distributed research infrastructure. Agreement that France, Italy and Greece host part of the observatory Events (yr-1) with 600 strings strings per building block Advantages: Access to regional funding (ERDF) Retain manpower Neutrino astronomy does not suffer If size exceeds a certain minimum Additional overhead small e.g: need multiple cables anyway Associated sciences benefit 19

20 Weak point? future is uncertain - future funding (see next slide) - Realization of phase-1 - funding available - prototypes working well - constraints from FR and IT on timescale are indeed severe - A large fraction (unfortunately not all), is in our own control - The FOM program will be instrumental in commissioning phase-1 and supporting investment application for phase If the project is somehow stopped (very unlikely, IMO): - we give back the remainder of the money - NB: If approved, the FOM Program will start (2015) when first line is already produced 20

21 View of the sky subtlety: -telescopes can look upward somewhat, at high energies. RX J1713 Vela X overlap: change of independent confirmation 21

22 Antares results data Uppsala 2000 Ivo van Vulpen 22 22

23 Antares results limits computed for 51 astrophysical objects most significant spot in the sky: 2.3s (p=2.1%) data Uppsala 2000 Ivo van Vulpen 23 23

24 Antares results - limits improved 40% compared to publication APj 760 (2012) 53 - Careful when comparing to IceCube. Uppsala 2000 Ivo van Vulpen 24 24

25 Antares results - limits improved 40% compared to publication APj 760 (2012) 53 - Careful when comparing - Cut-off expected for to IceCube. Galactic Sources - Antares rules the Southern Hemisphere below 10 TeV Uppsala 2000 Ivo van Vulpen 25 25

26 Antares results 3C279 p=10% Fermi-bubbles (1.2 excess) coincidence with flairing sources PRELIMINARY neutrinos coincident with GRB (none found) Uppsala 2000 dark matter annihilation in the Sun (very competitive limits) Ivo van Vulpen 26 26

27 String Deployment String Launching Fast mounting of optical modules Multiple deployments / cruise Autonomous unfurling from seabed Recovery of launcher vehicle 27

28 String Mechanical 2-12 April 2013: 5 deployments Deployment at a depth of 1000mTests (NIOZ boat) 20 miles off the coast of Motril, Spain Spain in-house designed cable (huge cost saving) Successful demonstration of deployment concept DOMs are horizontal Some issues with penetrators (understood and fixed) 28

29 IceCube Signal (starting track analysis) 4 evidence of cosmic neutrinos! - publication (excepted by Science) and results from muon analysis expected soon 29

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