G. RiccobeneIFAE, Pavia 19-21Aprile 2006 Astronomia a neutrini con km 3 sott’acqua e ghiaccio.

G. Riccobene IFAE, Pavia 19-21Aprile 2006

Astronomia a neutrini con km3 sott’acqua e ghiaccio


Why neutrino astronomy?

Neutrino astronomy aims at the identification of the sources of the UHECRs Neutrino astronomy aims at the identification of the sources of the UHECRs

• Neutrinos traverse space without being

deflected or attenuated

– They point back to their sources

– They allow to view into dense

environments

• Neutrinos are produced in high energy

hadronic processes

– They can allow distinction between

hadronic and leptonic acceleration

mechanisms

• Neutrinos traverse space without being

deflected or attenuated

– They point back to their sources

– They allow to view into dense

environments

• Neutrinos are produced in high energy

hadronic processes

– They can allow distinction between

hadronic and leptonic acceleration

mechanisms

Absorption lenght of CR in the Universe


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)


0

Neutral pion produced in pp collisions may produce the observed TeV fluxes

(SNR RX J1713.7-3946, Aharonian 2004,2005)

HE proton interaction on ambient p or

Beam dump in gas dense environment (SNR)

+

-

Muons and muon-neutrinos

HE proton

SN shells,clouds,..

Shock wave

Target protons

Beam dump in astrophysical jet environment (GRB,AGN,microQSO)

p n

Shock waves

Matter shells

HE proton

Target photons

pions

1

muons and neutrinos GRB (Waxman), AGN jets (Mannheim),

microQSO (Levinson)


The observation of TeV neutrino fluxes requires km2 scale detectors

neutrino

muon

Cherenkov light

~5000 PMT

Connection to the shore

neutrino

atmospheric muon

depth>3000m


Candidate sources and expected events

Diffuse fluxesGZK neutrinos 0.5 / year

GRB (Waxman) 50 / year

AGN (thin) (Mannheim) few / year

(thick) >100 / year

Point-like sourcesGRB (030329) (Waxman) 1-10 / burst

AGN (3C279) (Dermer) few / year

Galactic SNR (Crab) (Protheroe) few / year

Galactic MicroQuasar (Distefano) 1-100 / year

tot A

,min

E,min E N Z

,minE

N E ,dE E , P E ,E e

AT

Neutrino fluxProbability to produce a detectable muon (Eµ >Emin)

Earth transparency

Expected events in a 1 km2 detector


Status of collaborations

BAIKAL, AMANDA: taking dataNESTOR, ANTARES, NEMO R&D: under constructionICECUBE: under construction (expected 2010)KM3NET – Meditteranean : EU Design Study 2006-2008

AMANDAICECUBE

BAIKAL

ANTARES

2400 m

NESTOR

3800 m

NEMO

3500 m


Two neutrino telescopes

GX339-4SS433

Crab

VELA

South Pole Mediterranean

• In order to obtain the whole sky coverage 2 telescopes must be built

• The Galactic Centre is observable only from the Northern

Hemisphere

GX339-4SS433

Crab

VELA

Galactic Centre

HESS data


HESS Sources

Observable only from the Mediterranean


The largest detector up to date: AMANDA

Optical Module

AMANDA-II19 strings677 OMsDepth 1500-2000m

Effective Area 104 m2 (E TeV)

Angular resolution 2°


Atmospheric neutrinos

Atmospheric neutrinos is the background for cosmic neutrinos but in the same time an important calibration tool.

Neutrinos up to a few 100 TeV have been observed in AMANDA

Spectrum can be used to search for E-2 component

E2μ(E) < 2.9·10–7 GeV cm-2 s-1 sr-1 Limit on diffuse E-2 νμ flux (100-300 TeV):

horizontalvertical

Hulth, NOVE 2006


Point Source SearchSelected Sources

0.214.502SS433

1.255.3610Crab Nebula

0.405.214Cygnus X-1

0.775.046Cygnus X-3

0.383.7151ES1959+650

0.685.586Markarian 421

Flux Upper Limit 90%(E>10 GeV)

[10-8cm-2s-1]

Expectedbackgr.

(4 years)

Nr. of events

(4 years)

Source

selected objects → no statistically significant effect observed

… out of 33 Sources

Systematic uncertainties under investigation

Crab Nebula: MC probability to obtain an entry with at least this excess significance is 64%

Sensitivity ~2for 200 days of “high-state” and spectral results from HEGRA

Preliminary


The future of underice neutrino telescope: ICECUBE

The technology for underice detectors is reliable.

The next step is the construction of the km3 detector ICECUBE.

The technology for underice detectors is reliable.

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

17 m spacing along a string

Instrumented volume: 1 km3 (1 Gton)

First string deployed Jan 2005

IceCube will be able to identify

tracks from for E > 1011 eV

cascades from e for E > 1013 eV

for E > 1015 eVFebruary 20069 strings deployed

IceTop air shower array

80 pairs of ice Cherenkov tanks


ANTARES

ANTARES is installing a 0.1 km2 demonstrator detector close to Toulon

• 12 lines• 25 storeys / line• 3 PMTs / storey• 900 PMTs

~70 m

350 m

100 m

14.5 m

Submarine links

JunctionBox

40 km toshore

Anchor/line socket

to be deployed by 2005-2007

ANTARES

deployed

Line 1 in

February.

2006.


Operation 2006-01 (1st part) line 1 deployment

Waiting in Foselev hangar since 15th december…loaded on 13th feb 2006


ANTARES Sea Operations


Run 21240 Event 12505

= 101o

P(2,ndf) = 0.88

t [ns]

z [m

]

Antares preliminary

Real Data: atmospheric muons reconstructed

Result of Fit

Run 21240 Event 12527

= 146o

P(2,ndf) = 0.61

t [ns]

z [m

]


NEMO

The NEMO Collaboration is dedicating a special effort in:

• search, characterization and monitoring of a deep sea site adequate

for the installation of the Mediterranean km3;

• development of technologies for the km3 (technical solutions chosen

by small scale demonstrators are not directly scalable to a km3).

The NEMO Collaboration is dedicating a special effort in:

• search, characterization and monitoring of a deep sea site adequate

for the installation of the Mediterranean km3;

• development of technologies for the km3 (technical solutions chosen

by small scale demonstrators are not directly scalable to a km3).


The Capo Passero deep sea site

• The average depth is 3500 m, the distance from shore is 100 km.

• It is located in a wide abissal plateu far from shelf breaks and geologically stable.

• Optical properties of deep sea water are the best measured among investigated sites (absorption length close to optically pure water astro-ph\0603701)

• Optical background is low (25 kHz on 10’’ PMT at 0.5 s.p.e. threshold) and mainly due to 40K decay since the bioluminesce activity is extremely low.

• Underwater currents are very low (2.5 cm/s) and stable.

After eight years of activity in seeking and monitoring abyssal sites in the Mediterranean Sea the NEMO collaboration has chosen the Capo Passero site.The site has been propsed to ApPEC on january 2003 as candidate site for the installation of the km3.


• 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

Seawater optical properties in Toulon and Capo PasseroOptical properties have been measured in joint ANTARES-NEMO campaigns

in Toulon and in Capo Passero (July-August 2002)

NEMO data

ANTARES data

Average values 2850÷3250 m

•Light Absorption and attenuation lengths measured in Capo Passero don’t show seasonal dependence


Optical background in Toulon and in Capo Passero

Optical data measured in Capo passero are consistent with biological data: no luminescent bacteria have been observed in Capo Passero below 2500 m

15

20

25

30

35

0 7 14 21 28 35 42 49

Co

un

tin

g r

ate

(kH

z)

0.0%

0.5%

1.0%

1.5%

2.0% Tim

e abo

ve 200 kHz

Days

Spring 2003 data

30 kHz

Optical background rate is much higher in Toulon.


Present proposal for Detector Layout

• 1 main Junction Box

• 8 10 secondary Junction Boxes

• 60 80 towers

• 140 200 m between each tower

• 16 18 floors for each tower

• 64 72 PMT for each tower

• 4000 6000 PMTs

NEMO will be modular detector:

Main JB

1st Secondary JB……

Nst Secondary JB 8 10 towers

8 10 towers

Changes: distances, number of towers, tower length, shape (hexagonal), …

The tower geometry allows: good sensitivity to 100 GeV neutrinos

Aeff > 1 km2 at E ~10 TeV

feasibility of underwater operations

Electro-optical cable from shore

Primary Junction Box

Secondary Junction Boxes

tower

electro-optical cables network


Expected detector performaces

SensitivitySensitivity to point like fluxes Ev

-2 spectrum

NEMO 81 towers 140m spaced - 5832 PMTsIceCube 80 strings 125m spaced - 4800 PMTs

Geometry “flexibility”Effective area for different detector geometries

spacing spacingtowers floors140 m 40 m

300 m 40 m


The NEMO Phase 1

The NEMO Collaboration is undergoing the Phase 1 of the project, installing a fully

equipped deep-sea facility to test prototypes and develop new technologies for the km3

detector.

Shore laboratory port of Catania

Underwater test site: 25 km E offshore Catania at 2000 m depth

e.o. cable from shore

TSS Frame

To be completed in 2006

Junction Box

NEMO mini-tower(4 floors)

An electro-optical cable (10 fibres, 4 conductors) connects the shore laboratory, in the Port of Catania, with the underwater test site

underwater e.o. cable


The NEMO test site: a multidisciplinary laboratory

The ODE stationGEOSTAR SN-1 deep sea station

First data from 2000 m• GEOSTAR SN-1, a deep sea station for on-line seismic and environmental monitoring by

INGV. The NEMO test site is the Italian site for ESONET (European Seafloor Observatory

NETwork);

• ODE (Ocean noise Detection Experiment), for on-line deep sea acoustic signals

monitoring (4 hydrophones hydrophones 30 Hz - 40 kHz measurement of noise bkg for

neutrino acoustic detection ).


NEMO Phase-1: scheme and deployment schedule

300

m

Mini-Tower compacted

Mini-Tower unfurled

15 m

Deployment of JB and minitower summer 2006

Junction Box

NEMO mini-tower(4 floors, 16 OM)

TSS Frame

Deployedjanuary 2005


The Junction Box

Fiberglass external vessel

Power vessels electro-optical connector

The Junction Box hosts the data transmission and power distribution system

This solution permits to separate the corriosion and the pressure resistance problems

1 m


The tower

Optical modules

Floor control module

Tower assembly at test site


The NEMO Phase 2 project in Capo Passero

Goals

- Realization of an underwater infrastructure at 3500 m on the CP site

- Test of the detector structure installation procedures at 3500 m

- Installation of a 16 storey tower

- Long term monitoring of the site

Infrastructure- A building (1000 m2) located inside the

harbour area of Portopalo has been acquired. It will be renewed to host the shore station for power supply and data acquisition systems

- 100 km electro-optical cable (about 40 kW) purchsed. Deployment by Alcatel-Elettra.

Project completion planned in 2007

Portopalo di Capo Passero


KM3NeT

System and ProductEngineering

Information TechnologyShore and deep-sea

infrastructureSea surface

infrastructure

Risk AssessmentQuality Assurance

Resource Exploration Associated Science

Technical Design Report (and recommendation on installation site)

WO

RK

PA

CK

AG

ES

Partecipants: 34 istitutes from 8 countriesObiettivo: design study for a submarine high energy observatory open to multidisciplinary submarine scienceStart 2006. Finish 2009.Total Budget 20278 k€, UE funding 9000 k€

Physics Analysisand simulations


Summary

• First generation detectors Baikal and AMANDA have demonstrated the

feasibility of the high energy neutrino detection;

• The forthcoming km3 neutrino telescopes will be “discovery” detectors

with potential to solve HE astrophysics basic questions:

UHECR sources, HE hadronic mechanisms, Dark matter ...

• To fully exploit neutrino astronomy we need two km3 scale detectors, one

for each hemisphere;

• The under-ice km3 ICECUBE is under way, following the AMANDA

experience;

• The Mediterranean km3 neutrino telescope will be an powerful astronomical

observatory thanks to its excellent angular resolution; KM3Net feasibility

study for the km3 detector started on beginning of 2006;

• ANTARES deployed Line1 on Feb. 2006, atmospheric muons already

reconstructed;

• NEMO is installing the Test Site in Catania and building infrastructures in

Capo Passero.


NEMO in Capo Passero


The NEMO Collaboration

INFNBari, Bologna, Catania, Genova, LNF, LNS, Napoli, Pisa, RomaUniversitàBari, Bologna, Catania, Genova, Napoli, Pisa, Roma “La Sapienza”

CNRIstituto di Oceanografia Fisica, La SpeziaIstituto di Biologia del Mare, VeneziaIstituto Sperimentale Talassografico, Messina

Istituto Nazionale di Geofisica e Vulcanologia (INGV)

Istituto Nazionale di Oceanografia e Geofisica Sperimentale (OGS)

Istituto Superiore delle Comunicazioni e delle Tecnologie dell’Informazione (ISCTI)

Circa 100 ricercatori dell’INFN e dei principali enti di ricerca italiani coinvoltii

G. RiccobeneIFAE, Pavia 19-21Aprile 2006 Astronomia a neutrini con km 3 sott’acqua e ghiaccio.

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Transcript of G. RiccobeneIFAE, Pavia 19-21Aprile 2006 Astronomia a neutrini con km 3 sott’acqua e ghiaccio.