nemo project: towards the km cherenkov neutrino … project: towards the km3 cherenkov neutrino...
TRANSCRIPT
NEMO project: towards the
km3 Cherenkov Neutrino Telescope in the
Mediterranean Sea
Antonio Capone
INFN and University “La Sapienza”
Roma - Italy
Antonio Capone - INFN and University "La Sapienza", Roma - Italy UHE Neutrino Workshop - Beijing - April 23rd-25th 2
Layout of the talk
Introduction
Overview of the NEMO R&D activitiesSite exploration activities
Feasibility study
…
The NEMO Phase-1 projectStatus of the activities at the Catania Test Site
The NEMO Phase-2 projectShore and deep sea infrastructures at Capo Passero
Electro-optical cable
Conclusions and perspectives
G. Riccobene talk
Antonio Capone - INFN and University "La Sapienza", Roma - Italy UHE Neutrino Workshop - Beijing - April 23rd-25th 3
NEMO R&D activities towards a km3 neutrino
detector in the Mediterranean Sea
Site selectionSearch and characterization of a deep sea site with optimal characteristics:
depth, water optical properties, …
Long term monitoring of the site
Feasibility study of the km3 detectorSystem analysis of all the construction and installation issues
Optimization of the detector geometry by means of numerical simulations
Validation of the proposed technologiesAdvanced R&D and prototyping of the proposed technical solutions
Antonio Capone - INFN and University "La Sapienza", Roma - Italy UHE Neutrino Workshop - Beijing - April 23rd-25th 4
The NEMO collaboration
INFNBari, Bologna, Catania, Genova, LNF, LNS,
Napoli, Pisa, Roma
UniversitiesBari, Bologna, Catania, Genova, Napoli,
Pisa, Roma “La Sapienza”
CNRIstituto di Oceanografia Fisica, La Spezia
Istituto di Biologia del Mare, Venezia
Istituto 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)
More than 70 researchers from INFN and other Italian Institutes
Antonio Capone - INFN and University "La Sapienza", Roma - Italy UHE Neutrino Workshop - Beijing - April 23rd-25th 5
Neutrino Telescopes status
AMANDA
ICECUBE
Mediterranean
km3
BAIKAL
DUMAND
Pylos
La Seyne
Capo Passero
DUMAND R&D - finished
BAIKAL, AMANDA - taking data
ANTARES, NEMO, NESTOR - under construction / first data
ICECUBE, Mediterranean km3 - next generation
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
Antonio Capone - INFN and University "La Sapienza", Roma - Italy UHE Neutrino Workshop - Beijing - April 23rd-25th 6
GX339-4SS433
Crab
VELA
South Pole Mediterranean
• The whole sky coverage needs two telescopes in different Hemispheres
• The Galactic Centre is observable only from the Northern Hemisphere
GX339-4SS433
Crab
VELA
Galactic Centre
HESS data
Two km3 neutrino telescopes ??
Antonio Capone - INFN and University "La Sapienza", Roma - Italy UHE Neutrino Workshop - Beijing - April 23rd-25th 7
HESS Sources
Observable from the km3 in
the Mediterranean
Antonio Capone - INFN and University "La Sapienza", Roma - Italy UHE Neutrino Workshop - Beijing - April 23rd-25th 8
> 25 sea campaigns since 1998
– light transmission properties of deep sea water(AC9 transmissometer)
– optical background (custom devices)
– deep sea currents (RCM11 and RCM8 current metre) data analysis OGS
– nature and quantity of sediment material (Sediment trap) data analysis IBM
– seabed characteristics (cores and bottom profile) data analysis CEOM-ENI
Other sites explored
Lake Baikal, in collaboration with BAIKAL site evaluation group
Toulon (ANTARES site), in collaboration with ANTARES site evaluation group
Water optical propertiesAC9 (WetLabs)
Biofouling Sediments Optical background
(V. Balkanov et al. NIM 2002)
NEMO Site Selection Activity
Antonio Capone - INFN and University "La Sapienza", Roma - Italy UHE Neutrino Workshop - Beijing - April 23rd-25th 9
Sites investigated, ships
Capo Passero 3350 mUstica 3500 mAlicudi 3500 mCatania 2000 m
CONISMA R/V UNIVERSITATIS 48m
CNR R/V Thetis 32 m
CNR R/V Urania 62 m
NATO R/V Alliance 110m
Antonio Capone - INFN and University "La Sapienza", Roma - Italy UHE Neutrino Workshop - Beijing - April 23rd-25th 10
Absorption and attenuation lengths
Capo Passero 2850-3250 m
Antonio Capone - INFN and University "La Sapienza", Roma - Italy UHE Neutrino Workshop - Beijing - April 23rd-25th 11
Seasonal dependence of
oceanographical (Temperature and
Salinity) and optical (absorption
and attenuation) properties has
been studied in Capo Passero
Variations are only observed in
shallow water layers
Aug 02 (3 profiles superimposed)
Mar 02 (4 profiles superimposed)
May 02 (2 profiles superimposed)
Dec 99 (2 profiles superimposed)
Data taken in:
temperature salinity a440 c440
Aug 03 (2 profiles superimposed)
Water optical properties: no seasonal dependence
Antonio Capone - INFN and University "La Sapienza", Roma - Italy UHE Neutrino Workshop - Beijing - April 23rd-25th 12
Capo Passero 2850-3250 m
! absorption @ 440nm
Water optical properties: no seasonal dependence
! attenuation @ 440nm
Antonio Capone - INFN and University "La Sapienza", Roma - Italy UHE Neutrino Workshop - Beijing - April 23rd-25th 13
Deep-Sea sites optical water properties
Comparison of Capo Passero and Toulon sites
Optical water properties have been measured in the summer 2002 in Capo Passero
and Toulon in two joint NEMO-ANTARES campaigns
Absorption lengths measured inCapo Passero site arecompatible with optically puresea water data
Large differences betweenToulon and Capo Passero areobserved in the blue region
A campaign has also beenperformed to measure waterproperties on the Baikal site
Antonio Capone - INFN and University "La Sapienza", Roma - Italy UHE Neutrino Workshop - Beijing - April 23rd-25th 14
NEMO device (8’’ PMT at 0.3 spe)
! Toulon 58.0±3.0 kHz
! Capo Passero 28.5±2.5 kHz
PMT 2+power
PMT dark current 7 kHz
PMT dark current 7 kHz
Optical background in Capo Passero and Toulon
PMT 1+ DAQ
PMT 2
Antonio Capone - INFN and University "La Sapienza", Roma - Italy UHE Neutrino Workshop - Beijing - April 23rd-25th 15
Optical background in Capo Passero
Data taken in collaboration
with ANTARES
Dead time:
Fraction of time with
rate > 200 kHz
" PMT: 10”
" Thres: ~.5 SPE
Background depth
dependence in
agreement with biology
data (bioluminescent
bacteria count)
Antonio Capone - INFN and University "La Sapienza", Roma - Italy UHE Neutrino Workshop - Beijing - April 23rd-25th 16
Typical time sequence of Optical noise rate in Capo Passero
Measured with test 1Courtesy J.P. Schuller
Counting rate (kHz)
1
10
100
1000
10000
0 5 10 15 20 25 30
Time (mn)
.35 spe
No luminescent bacteria have been
observed in Capo Passero below
2500 m
Bioluminescence
Antonio Capone - INFN and University "La Sapienza", Roma - Italy UHE Neutrino Workshop - Beijing - April 23rd-25th 17
Effect of biofouling on optical module
transparency in Capo Passero site
D
B
C
A
• Setup realized by the ANTARES collaboration
• Four glass spheres with blue LED emitters and 28 PIN
diodes
• Allows measurement at different polar angles of the
transparency loss due the bio-film growth
• Immersed at the Capo Passero site for 18 months (April
2003 - October 2004)
-100 -50 0 50 100
0.92
0.96
1.00
!
T (
t=1 y
ear)
/ T
(t=
0)
Transparency after
1 year
"
-90°
0°
+90°
Antonio Capone - INFN and University "La Sapienza", Roma - Italy UHE Neutrino Workshop - Beijing - April 23rd-25th 18
Trap-KM4
0
100
200
300
Aug Oct Dec Feb Apr Jun Aug Oct Dec Feb Apr Jun Aug Oct Dec
Time
TM
F (
mg
m-2
d-1
)
1999 2000 2001
Sediment samples collected over more than 3 full years: Aug 1999-May 2000 andJuly-December 2001(analysed). Other periods under analysis
Etna eruption
July 2001
Sedimentation rate in Capo Passero site - 1
Antonio Capone - INFN and University "La Sapienza", Roma - Italy UHE Neutrino Workshop - Beijing - April 23rd-25th 19
1 jan 1 mar 1 jun 1 sep 31 dec0
50
100
150
200
250
300
350
date
TM
F (
mg
m-2
day
-1)
NEMO 1999 data
NEMO 2000 data
NEMO 2001 data
ANTARES 1997 data
I1 1997 data
I1 1998 data
NorthernIonian Sea
Sedim
ent
flux (
mg m
-2 d
-1)
Sedimentation rate in Capo Passero site - 2
Antonio Capone - INFN and University "La Sapienza", Roma - Italy UHE Neutrino Workshop - Beijing - April 23rd-25th 20
Two current metres and a sediment trap aremoored in Capo Passero Region since 1998 up to --> today .
Deep sea water currents are low and stable: average value=3 cm/s, max. value=10 cm/s
Seabed 3350 m
Current meter 3050 m
Current metre 2900 m
Sediment trap 3000 m
Oceanographic data measured in Capo Passero
Antonio Capone - INFN and University "La Sapienza", Roma - Italy UHE Neutrino Workshop - Beijing - April 23rd-25th 21
The Capo Passero siteIn a seven year activity (1998-2005) the NEMO collaboration has selected a deep sea site
offshore Capo Passero (Sicily) (36° 16’ N, 16° 06’ E) with optimal oceanographycal and
environmental properties
The site has been proposed in January 2003 to ApPEC
as a candidate for the km3 installation
• Depths of more than 3500 m are reached at ~ 100 km
distance from the shore
• Water optical properties are the best observed in the
studied sites:
La ! 70 m @ ! = 440 nm)
• Optical background from bioluminescence is extremely
low
• Stable water characteristics
• Deep sea water currents are low and stable:
average value=3 cm/s, max. value=10 cm/s
• Wide abyssal plain, far from the shelf break, allows for
possible reconfigurations of the detector layout
Capo Passero 3400 m
Toulon 2400 m
Pylos 3800:4000 m
ANTARES
NEMONESTOR
Antonio Capone - INFN and University "La Sapienza", Roma - Italy UHE Neutrino Workshop - Beijing - April 23rd-25th 22
Towards the Mediterranean km3
Electro-optical cable:
construction and
deployment
Data transmission system
Underwater
connections
Detector:
design and construction
deployment and recovery
Power transmission
system
Electronics
Power Distribution
Acoustic positioning
Antonio Capone - INFN and University "La Sapienza", Roma - Italy UHE Neutrino Workshop - Beijing - April 23rd-25th 23
Feasibility study for the km3 detector
main EO cable
main Junction Box
secondary JB
“tower”
Detector architecture issues
Reduce the number of structures to reduce the
number of underwater connections and allow
operation with a ROV
Detector modularity
9 * 9 = 81 “Towers” with
3 dimensional and non
homogeneous distribution
of sensors
Antonio Capone - INFN and University "La Sapienza", Roma - Italy UHE Neutrino Workshop - Beijing - April 23rd-25th 24
Possible extragalactic sources and fluxes
Learned Mannheim
AGN
GZK
p# AGN corespp AGN cores
p# blazar
GRB
WB Limit
Diffuse neutrino fluxes
Stecker
Nellen
Mannheim
Bierman
Waxman
Antonio Capone - INFN and University "La Sapienza", Roma - Italy UHE Neutrino Workshop - Beijing - April 23rd-25th 25
Candidate sources of High Energy Neutrinos and
expected events
Diffuse fluxes
GZK neutrinos 0.5 / year
GRB (Waxman) 50 / year
AGN (thin) (Mannheim) few / year
(thick) >100 / year
Point-like sources
GRB (030329) (Waxman) 1-10 / burst
AGN (3C279) (Dermer) few / year
Galactic SNR (RXJ1713, Vela) (Aharonian, Vissani) few / year
Galactic MicroQuasar(Distefano, Aharonianet et al.) 1-100 / year
( )( ) ( ) ( ) ( )tot A
,min
E
,min E N Z
,min
E
N E ,dE E , P E ,E e
AT
!
!
µ
µ µ "# $
! ! ! !µ ! µ
$= % $ & &'
Neutrino fluxProbability to produce a
detectable muon (E" >Emin)Earth transparency
Expected
events in a
1 km2
underwater
Cherenkov
Neutrino
Telescope
Antonio Capone - INFN and University "La Sapienza", Roma - Italy UHE Neutrino Workshop - Beijing - April 23rd-25th 26
The NEMO “Tower”
Optical Modules
Electronics container
Mechanical structures for the km3 studied in order to optimize
the detector performance.
Modular structure composed by a sequence of 15 m long
arms (storeys) interconnected by tensioning cables. Full
height 750 m.
Power and data cables are kept separated from the
tensioning ones.
Antonio Capone - INFN and University "La Sapienza", Roma - Italy UHE Neutrino Workshop - Beijing - April 23rd-25th 27
Tower detector performance
Sensitivity
Sensitivity to point-like sources (Ev-2 spectrum)
NEMO 81 towers 140m spaced - 5832 PMTs
IceCube 80 strings 125m spaced - 4800 PMTs
Reconfigurability
Effective areas with different element spacing
Tower Floor
spacing spacing
Black line 140 m 40 m
Red square 300 m 60 m
Black points 300 m 40 m
NEMO search bin 0.3°
IceCube search bin 1°
IceCube simulations from Ahrens et al. Astrop. Phys. 20 (2004) 507
Antonio Capone - INFN and University "La Sapienza", Roma - Italy UHE Neutrino Workshop - Beijing - April 23rd-25th 28
Angular resolution and pointing accuracy
2659 8deg
0.19 0.02deg
k
!
"= ±
= ±
(Simulated time = 1 year)
2
22
2 212
moondN
k ed
!µ "
!
! "
#$ %& '= #& '( )
100 days needed to observe a 3$ effect
Observation of the Moon
shadowing effect on the flux
of atmospheric muons
Antonio Capone - INFN and University "La Sapienza", Roma - Italy UHE Neutrino Workshop - Beijing - April 23rd-25th 29
Effects of environmental properties on detector
performance
0 1 2 3
0.9
1.0
Log10 Eµ (TeV)
Aef
f (t
) /
Aef
f (t=
0)
6 months
1 year
5 years
10 years
Aeff µ vs Eµ
Optical background rate Biofouling
# 20 kHz
# 60 kHz
# 120 kHz
Effective areas for different
background rates
Upgoing muons with E-1 spectrum
Trigger + Quality Cuts
Reduction of effective area due to loss of
transparency of the Optical Modules
Transparency loss as measured in Capo
Passero
Antonio Capone - INFN and University "La Sapienza", Roma - Italy UHE Neutrino Workshop - Beijing - April 23rd-25th 30
The NEMO Phase-1 project
Double armed cable
2.330 m
Single armed cable
20.595 m
North branchNorth branch
5.220 m5.220 m
South branchSouth branch
5.000 m5.000 m
BU
SN-1Shore stationShore station
NEMO Phase-1
Underwater infrastructure realized by the
Laboratori Nazionali del Sud to test
detector prototypes
A seismic and environmental observatory
of INGV has been installed and connected
to the EO cable
• Realization of a subsystem of the km3
including all the key elements of the detector
• Shore and deep sea infrastructures already realized
• Project jointly funded by INFN and MIUR
• Realization of main components completed
• Integration and test under way
See G. R
iccobene talk
Antonio Capone - INFN and University "La Sapienza", Roma - Italy UHE Neutrino Workshop - Beijing - April 23rd-25th 31
The NEMO Phase 2 project
A deep sea station on the Capo Passero site
OBJECTIVES
- 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 UNDER CONSTRUCTION
- Shore station in Portopalo di Capo Passero
- 100 km electro optical cable
- Underwater infrastructures
STATUS
- Electro-optical cable (>50 kW, 20 fibres) ordered
- A building (1000 m2) located inside the harbour area of
Portopalo has been acquired. Procedures for its renovation
started
- Project completion planned in 2007
CapoPassero
site
Antonio Capone - INFN and University "La Sapienza", Roma - Italy UHE Neutrino Workshop - Beijing - April 23rd-25th 32
The Phase-2 electro-optical cable
DC solution with sea return
Working Voltage 10 kV
Power > 50 kW
Antonio Capone - INFN and University "La Sapienza", Roma - Italy UHE Neutrino Workshop - Beijing - April 23rd-25th 33
Phase-2 Electro Optical cable termination
To shore
Cable In
VDC 10 kV
Cable Out
VDC 10 kV
DC/DC
5-10 kW
400 V-DC Out
Fibre Out
400 V-DC Out
Fibre Out
ROV connector
ROV connector
DC/DC
5-10 kW
JB
DC/AC
TowerTower
380 V-AC Out
Fibre Out
main EO cablemain Junction Box
secondary JB
“tower”
Antonio Capone - INFN and University "La Sapienza", Roma - Italy UHE Neutrino Workshop - Beijing - April 23rd-25th 34
View of the cable landing area
Shore Station
Antonio Capone - INFN and University "La Sapienza", Roma - Italy UHE Neutrino Workshop - Beijing - April 23rd-25th 35
The Shore Station (project)
View from the north side
Antonio Capone - INFN and University "La Sapienza", Roma - Italy UHE Neutrino Workshop - Beijing - April 23rd-25th 36
NEMO: status and perspectives
Site choiceThe site selected offshore Capo Passero shows optimal characteristics for the installation
of the km3-scale Deep-Sea Cherenkov Neutrino Telescope
Proof of the technical and budgetary feasibility of the km3
Checked in a complete feasibility study performed in collaboration with some companies
with well proven experience in underwater operations
Validation of the proposed technologies for the km3
Realization of Phase-1 (2006) and Phase-2 (2007) projects
Realization of shore and deep sea infrastructures at Capo Passero
Future developmentsEurope funded (10M#) the KM3NeT Design Study. ANTARES, NEMO and NESTOR
physicists working together … towards the realization of a km3 detector
Antonio Capone - INFN and University "La Sapienza", Roma - Italy UHE Neutrino Workshop - Beijing - April 23rd-25th 37
Summary: the km3Neutrino Telescope in the
Mediterranean Sea: a long effort …
for (hopefully) a great result
… let’s realize the “forbidden dream” …”
Antonio Capone - INFN and University "La Sapienza", Roma - Italy UHE Neutrino Workshop - Beijing - April 23rd-25th 38
Muon fluxes and depths in water
%µ
(cm
-2 s
r-1 s
ec-1
)
AMANDA
Toulon
Capo Passero
Methoni
%µ
(cm
-2 s
r-1 s
ec-1
)
Antonio Capone - INFN and University "La Sapienza", Roma - Italy UHE Neutrino Workshop - Beijing - April 23rd-25th 39
Seismic activities in Mediterranean area
Earthquakes registered if magnitudo > 4-5 Richter