1. P.Kooijman, UVA-GRAPPA, UU, Nikhef
Status of KM3NeT
P.Kooijman, UVA-GRAPPA, UU, Nikhef
On behalf of KM3NeT
ICRC, Beijing, 2011

2. Most manageable sea in Northern hemisphere→ Mediterranean
Motivation
Build the worlds most sensitive neutrino telescope with a view incorporating the Galactic centre → Northern hemisphere
Most manageable sea in Northern hemisphere→ Mediterranean
August 15, 2011, Beijing

3. Experience with NEMO, NESTOR and especially ANTARES
August 15, 2011, Beijing

4. Progress and Planning 2009 - Design Study completed
Technical Design Report
Preparatory Phase will be completed
2010 – Technical Decisions
2011/2012 – Prototyping
2011 – Funding requests in several countries (~50% of 220 M€ budget)
2011 – Prepare the collaboration structure for after PP
2013 – Preparation for mass production
Finalise design
Sourcing materials and tendering
2014 – Start Construction
August 15, 2011, Beijing

5. Sensor Module Concentrator ring
Increase of Photocathode area by %
Digital Optical Module:
17” sphere
31 photomultiplier tubes (3”)
All HV and readout and control electronics inside
Features:
Photon counting
Uniform acceptance
Coincidences
Anomalous large pulse rejection
Large photocathode area per pressure feed-through
Two manufacturers have prototype PMTs with good specifications:
ETEL (USA/UK)
Hamamatsu (Japan)
Two further manufacturers are preparing prototype PMTs
MELZ (Russia)
Zhen Chuang (China)
August 15, 2011, Beijing

6. Read out Electronics: Low power Cockroft-Walton HV base
Time over threshold of each PMT
External DC/DC converter for galvanic isolation
FPGA central logic
PC functionality
External or internal timestamping
I2C or SPI bus for slow control
August 15, 2011, Beijing

7. Timing accuracy 50 ps shore to DOM over 100 km
Fibre-optic read-out
Timing accuracy 50 ps shore to DOM over 100 km
August 15, 2011, Beijing

8. Vertical Structure Tower Structure: 20 storeys with each 2 DOMs
6 m length
40 m between
Alternately perpendicular
Connected by four 5 mm Dyneema ropes
Buoy at top
Anchor at bottom
Stacked for deployment (4x5)
Unfurling from the seafloor
860 m high
Drag gives top displacement of 150 m at 30 cm/s water current (very rare) 6m
Advantage length:
Triggering and low energy
Torsional stability
August 15, 2011, Beijing

9. Seafloor Layout TDR Present reference ~6 km3 instrumented volume
Network of smaller detectors
Deployment and connection easier
180 m inter tower distance
Less “alignment”
Other option very sparse for high energies
~6 km3 instrumented volume
August 15, 2011, Beijing

10. Optimisation Optimisation is ongoing taking into account:
Optimal sensitivity for Galactic sources
Cut-off power spectrum à la RXJ1713
Safe and reliable deployment
(Maintenance of) Seafloor cable network
Power distribution
Data network
Risk analysis
Tracking
Backgrounds
August 15, 2011, Beijing

11. Status now for Galactic Sources
RXJ1713 flux assuming 100% hadronic
TDR
154 in 1100 m radius
50 in 650 m radius
50 in 500 m radius
3-4 signal/year
4-5 background /year
Depends on quality cuts
Only up-going tracks
Can go 10-20º above?
For showers > 10 PeV
15-20 km3
August 15, 2011, Beijing

12. Great Progress
Care to join?