A sensor architecture for neutrino telescopes
on behalf of the KM3NeT consortium
Els de Wolf
Thank you, Claudio!Thank you, Claudio!
Buoy
OM
OM
OM
OM
OM
10 kV / 400V
~2.6 km3
300 slender strings6000 optical modules~100 MEuro
Branch cable network on the seabed Junction box
Features of the architecture
Flexible and slender string structure Optical fibre network for communication Single high pressure transition per storey Few (active) components in the deep‐sea No application specific components in the deep-sea No fault (leak)propagation from one storey to the other
or from one string to the other One wet‐mateable connections per string
(Innovative deployment: 1/~15) Minimum of material in the deep sea ‘Low’ cost
3
reliability
Analysis of DUMAND/Antares/NEMO/Nestor
Flexible string works Fibre network works Reliability can be further enhanced Costs can be reduced
4
Reliability analysis
Minimise probability of water leaks Minimise number of pressure transitions
5
1(2?) transition (1 OM)
~Same photocathodeElectronics and all other
instrumentation a single container
9 transitions (3 OMs + Hydrophone)1 transition
multi-PMT optical module
No separate electronics container Single pressure transition per storey
(optical module = storey)
6(talk Paul Kooijman)
7
Nikhef Open Day
10/10/2009
Temperature measurements in multi-PMT optical module
Sensor concept for readout&DAQ
Laser light from shore is modulated in the (optical) module with the data through reflective modulators.
Readout on heart-beat of laser pulses from shore Front-end functionality moved to shore.
8
laser
Sensor architecture concept
Unique optical connection between each module and the shore.
9
laser
(talk Jelle Hogenbirk)
Reliability of readout/DAQ
Only few non-specific active components in the deep sea
No application-specific components in the deep sea
10
Designed to our specification by telecom technical consultancy company CIP, using their off the shelf and Bellcore certified items.
Communication network
10 Gb/s bandwidth, 50 GHz channel spacing Passive Optical Network using DWDM Fibre propagation time over 100 km
measured with precision < 100 ps
Electro-optical backbone
Flexible hose Oil filled, run at equipressure Break out at each storey Wet-mateable connection to node in branch cable
12
No propagation of failure of one storey to another
(talk Eric Heine)
First reference model
Mechanics of slender string
Minimum of material in the deep sea
13
Two dyneema ropes for mechanical strength
Simple structure to support optical module
Slender string
20 storeys String master module included in
break-out-box at storey 9 Low drag Relatively easy to deploy
Single wet‐mateable connection per string
(innovative deployment: very few)
14
Buoy
OM
OM
OM
OM
OM
BOB &DWDM
BOB
Anchor
Rope
Storey
30m
570m
100m
EOC (2 fiber + 2 Cu)
DU_CON(talk Eric Heine)
Realisation speed up
Enlarge weather window for deployment Compact and light deployment structures
Increase deployment rate Many strings in a single sea operation.
Early start of construction strings Can start while on-shore electronics is still in
development
15
16
10 kV / 400V
Junction box
Sea floor: branch cables with nodes
Compact deployment of strings
Sea floor network of branch cables with nodes
node
17
Unfurling of the string
18
Connect to node in the branch cable
~2.6 km3
300 slender strings6000 optical modules~100 MEuro
Effective area
19
Simulation and reconstruction effort started late, but is ongoingPreliminary results are promising.
Claudio Kopper
130 m string distanceUpgoing tracks only
Effective area compared to Antares
20
Antares
Energy Antares Factor
100 GeV 8x10-5 m2 - 5 (?)
1 TeV 0.005 m2 0.02 m2 5
10 TeV 0.5 m2 20 m2 40
100 TeV 3m2 120 m2 40
1 PeV 20 m2 500 m2 25
Rough comparison
Summary and conclusions
Sensor architecture with slender strings is feasible Based on experience of pre-decessors Designed for high reliable Cost effective Easy to deploy
Further improvements Improvement/avoidance wet-mateable connections Reconstruction
Preparatory phase Prototype string mechanics Prototype electro-optical cable Detailing readout and DAQ Design assembly lines for OM and string Detailing seafloor network
21
Engineering effort together with industry started
(first ideas documented)
Thank you!
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