high energy neutrino astronomy

P. Piattelli, CRNT meeting, Paris 16-17 december 2004

High Energy Neutrino AstronomyStatus and perspectives of the high

energy neutrino observatories

Paolo Piattelli, INFN Laboratori Nazionali del Sud Catania


Layout of the talk• High Energy Neutrino Astronomy

– Scientific motivations– Experimental techniques

• Status of the presently active neutrino detector projects

– The currently active neutrino detectors: Baikal and Amanda– The ongoing projects: Antares, Nestor, Nemo

• What comes next– The km3 at the South Pole: IceCube– The km3 in the Mediterranean sea: KM3NeT

• Conclusions and outlook


Why neutrino astronomy?• Neutrinos traverse space without being deflected or

attenuated– They point back to their sources– They allow to view into dense environments– They allow to investigate the Universe over cosmological

distances• Neutrinos are produced in high energy hadronic

processes– They can allow distinction between hadronic and leptonic

acceleration mechanisms• Neutrinos could be produced in Dark Matter

annihilation


Particle propagation in the Universe

Photons are absorbed on dust and radiationProtons are deviated by magnetic fieldsExtremely high energy protons interact with background radiationOnly neutrinos are direct

1 parsec (pc) = 3.26 light years (ly)

High energy particles > 1017

eV

gamma rays (0.01 - 1 Mpc)

protons E>1019 eV (10 Mpc)

protons E<1019 eV

neutrinos

Cosmic accelerator


Particle astrophysics with telescopes


Neutrino production in cosmic accelerators

Proton acceleration

• Fermi mechanism

proton spectrum dNp/dE ~E-2

Neutrino production• Proton interactions

p p (SNR,X-Ray Binaries)

p (AGN, GRB, microQSO)

• decay of pions and muons

Astrophysical jet

Particle accelerator

electrons are responsible for gamma fluxes (synchrotron, IC)F. Halzen


Principles of neutrino astronomyNeutrino telescopes search for muon tracks induced by neutrino interactions

The downgoing atmospheric flux overcomes by several orders of magnitude the expected fluxes induced by interactions.

On the other hand, muons cannot travel in rock or water more than 50 km at any energy

Upgoing and horizontal muon tracks are neutrino signatures


Principles of neutrino astronomy

neutrino

muon

Cherenkov light

~5000 PMT

neutrino

Flux estimate need km3 scale detectors

C:\Programmi\QuickTime\QuickTimePlayer.exe c:\windows\profiles\desktop\agenda2000\movie.avi


The HE neutrino telescope world map80’s: DUMAND R&D90’s: BAIKAL, AMANDA, NESTOR2k’s: ANTARES, NEMO R&D2010: ICECUBE

Mediterranean KM3 ?

AMANDAICECUBE

Mediterraneankm3

BAIKAL

DUMAND

Pylos

La Seyne

Capo Passero


A closer look at the Mediterranean Sea

ANTARES

3800:4000 m

2400 m

3400 m

NEMONESTOR


Baikal192 OM arranged in 8 strings, 72 m heighteffective area >2000 m2 (E>1 TeV)

3600 m

1366

m

• Successfully running since 10 years• Atmospheric neutrino flux measured• Further upgrades planned, but km3 hardly reachable


Amanda

Optical Module

AMANDA-II19 strings677 OMsDepth 1500-2000m

Effective Area 104 m2 (E TeV)Angular resolution 2°

above horizon: mostly fake events

below horizon: mostly atmospheric

959 events

The AMANDA sky map


The ANTARES neutrino telescope• string based detector • 12 lines• 900 PMTs• 2400 m deep

~70 m

350 m

100 m

14.5 m

Submarine links

JunctionBox

40 km toshore

Anchor/line socket

a storey


ANTARES status and realization plan

• 2003: Deployment and operation of two prototype lines

• Several months of data taking

• Technical problems(broken fiber, water leak)

no precise timing,no reconstruction.

• Early 2005: 2 upgradedprototype lines

• Mid-2005: Line 1• 2007: Detector completed


NESTOR• Tower based detector• Up- and downward looking PMTs• 3800 m deep• Dry connections• First floor (reduced size) with

12 PMTs deployed and operated in 2003


NEMO

The NEMO Collaboration has dedicated special efforts 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 (Capo Passero near Catania, depth 3400 m)

Modular detector concept based on semi-rigid structures16 storey towers with 4 OM per storey20 m storey length40 m spacing between storeys

Underwater connections


NEMO Phase 1 project

2.330 mDouble Armed Cable

20.595 m Single Armed Cable

Drop cable 2Drop cable 25.220 m5.220 m

Drop cable 1Drop cable 15.000 m5.000 m

joint BUjoint

joint

NEMO Phase 1 LabLong term tests for:underwater connections, electronics, mechanical structures, optical and acoustic detectors.

Multidisciplinary laboratory (will host an on-line underwater seismic station of the Istituto Nazionale di Geofisica e Vulcanologia) SN-1

• Realization of a detector subsystem including all critical components

• Site infrastructures at 2000 m already realized 30 km offshore Catania

• Project completely funded by INFN and MIUR• Completion foreseen in 2006


The Catania Test Site and ESONETThe NEMO test site in Catania will also host SN-1 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).


NEMO Phase 2A deep water station at the Capo Passero site

PROPOSED INFRASTRUCTURE- Shore station at Portopalo di Capo

Passero to host the power system the data acquisition and detector integration facilities

- 100 km electro optical cable- Underwater infrastructures (main

junction box)- Two intermediate connection

stations in shallow and medium deep waters for interdisciplinary activities (agreement with INGV and SACLANTCen)


ICECUBEThe technology for underice detectors is well established.The next step is the construction of the km3 detector ICECUBE.

• 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)• First string to be deployed in january

2005


Status of the IceCube project many reviews – international and within the U.S. - strongly emphasize

the exciting science which can be performed with IceCube

in Jan 2004, the U.S. Congress approvedthe NSF budget including the full IceCube MRE

significant funding approved also in Belgium, Germany and Sweden

in Feb 2004, NSF conducted a baseline review “go ahead”

deployment over 6 years IceCube strings IceTop tanks4 8 Jan 200516 32 Jan 200632 64 Jan 200750 100 Jan 200868 136 Jan 200980 160 Jan 2010

From O. Botner, Neutrino 2004


Do we need 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

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


Sky coverage

TeV sourcesQSO

Galactic centre

Galactic coordinatesMediterranean km3

ICECUBE

1.5 sr common view per day


KM3NeT: a Design Study for the km3

Astroparticle Physics Physics Analysis System and ProductEngineering

Information Technology Shore and deep-seastructure

Sea surfaceinfrastructure

Risk AssessmentQuality Assurance Resource Exploration Associated Science

A Technical Design Report (including site selection) for a Cubic kilometre Detector in the Mediterranean

WO

RK

PA

CK

AG

ES

• 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

The experience and know how of the ANTARES, NESTOR and NEMO collaborations is merging in the KM3-NET activity


Objectives and scopes of the KM3NeT DS

• Critical review of current technical solutions• Thorough tests of new developments• Comparative studies of sites and recommendation

on site choice• Assessment of quality control and assurance• Exploration of possible cooperation with industry• Investigation of funding and governance models

Establish path from current projects to the KM3

Expected outcomeIn three years a complete Technical Design Report for the KM3 will be produced


Exploitation model of the future KM3 facility

• Reconstructed data will be made available to the whole community

• Observation of specific objects with increased sensitivity will be offered

• Close relation to space and ground based observatories will be established (alerts for GRBs, Supernovae, etc…)

• “Plug-and-play solutions for detectors of associated science

Goal: facility exploited in multi-user and interdisciplinary environment


Associated science

• Great interest in long term deep-sea measurements in many different scientific communities:

– Marine biology– Ocenography– Environmental science– Geology and geophysics– …

• Substantial cross-links to ESONET (the European Sea Floor Observatory Network)

• Plan: include the associated science communities in the design phase to understand and react to their needs and make use of their expertise (e.g. site exploration)


Actions in the new I3 proposal• Networking

– A collaboration between the european projects (Antares, Nestor, Nemo) has been already established with KM3NeT)

– Increase collaboration with other neutrino projects (Baikal, Amanda, IceCube)

– Develop collaborations with gamma ray and space based observatories

– Other common fields of interest may be: massive computer simulations, development of common databases and source catalogues, development of computing and analysis tools

• JRAs– Overlap with KM3NeT should be avoided– Development of new detection methods for future neutrino

detectior projects (radio detection, acoustic detection, …)• Transnational access

– All the european existing projects can provide access for interdisciplinary studies as the future KM3NeT will do


Conclusions• Baikal and Amanda have demonstrated the

feasibility of the high energy neutrino detection• Three projects in the Mediterranean are under way:

– Antares and Nestor are currently under construction (first data taken)

– NEMO is pursuing R&D for technical solutions for the km3– All three collaborations together in a common effort

towards the km3• To fully exploit neutrino astronomy we need 2 km3

scale detectors, one for each emisphere:– IceCube is starting construction soon and will be

completed by 2010– KM3NeT aims at producing a complete Technical Design

Report in 2008


Remarks on EU applications

• The EU applies rather stringent and formal rules. These rules are not laws of nature - so physicists tend to ignore them!

• Writing proposals:– Take the evaluation criteria seriously:

• European added value• Scientific and technological excellence• Relevance of the objectives of the scheme• Quality of the management

– Read all available EU documentation and learn “EUish”• Evaluation process

– Well structured and transparent from inside …– … but completely opaque from the outside!– It helps a lot to take part in the EU evaluations

Lessons learned with the successful KM3NeT experience (from Uli Katzt, KM3NeT coordinator)


End of presentation


Next slides are spares


ANTARES: first deep sea data

• Rate measurements: Strong fluctuation of bioluminescence background observed

10min 10min

Rate (kHz)

time (s)

Constant baseline ratefrom 40K decays


ANTARES: long term measurements

baseline rate (kHz)

burst fraction

time

• Also measured: current velocity and direction, line heading and shape, temperatures, humidities, ...

• Important input for preparation & optimization of ANTARES operation.

baseline rate =15-minute average

burst fraction =time fraction above1.2 x baseline rate


NESTOR: reconstruction of muon tracks• Track reconstruction using arrival

times of light at PMs.• Ambiguities resolved using signal

amplitudes in up/down PM pairs.

PMcalibration


The HE neutrino telescope world map80’s: DUMAND R&D90’s: BAIKAL, AMANDA, NESTOR2k’s: ANTARES, NEMO R&D2010: ICECUBE

Mediterranean KM3 ?

AMANDAICECUBE

Mediterraneankm3

BAIKAL

DUMAND

Pylos

La Seyne

Capo Passero

ANTARES

3800:4000 m

2400 m

3400 m

NEMONESTOR


Scientific goals• Astronomy via high energy neutrino observation

– Production of high energy neutrinos in the universe (acceleration mechanisms, top-down scenarios, …)

– Investigation of the nature of astrophysical objects– Origin of high energy cosmic rays

• Indirect search for Dark Matter• New discoveries• Associated science


NEMO Phase 1 projectA step towards the km3 detector

EO CABLEEO CABLE

Length – 25 km10 Optical Fibres ITU- T G-652

6 Electrical Conductors 4 mm2

• Realization of a detector subsystem including all critical components

• Site infrastructures at 2000 m already realized 30 km offshore Catania

SHORE LABORATORYSHORE LABORATORY

Project completely funded (jointly by INFN and MIUR)Completion foreseen in 2006

UNDERWATER LABUNDERWATER LAB

high energy neutrino astronomy

Documents

active neutrino detectors

km3 search

outlookwhy neutrino

icecubemediterranean

nextthe km3

icecubethe km3

km3 scale detectorsthe

km3 technical solutions