Status of KM3NeT (Detector Design Optimisations) Christopher Naumann, CEA Saclay – IRFU / SPP for the KM3NeT consortium 44 th Reconcontres de Moriond,

Status of KM3NeTStatus of KM3NeT(Detector Design Optimisations)(Detector Design Optimisations)

Status of KM3NeTStatus of KM3NeT(Detector Design Optimisations)(Detector Design Optimisations)

Christopher Naumann,Christopher Naumann,

CEA Saclay – IRFU / SPPCEA Saclay – IRFU / SPPfor the KM3NeT consortiumfor the KM3NeT consortium

4444thth Reconcontres de Moriond, Reconcontres de Moriond, La Thuile, Italy , 1La Thuile, Italy , 1stst-8-8thth February 2009 February 2009

"Status of KM3NeT Design Optimisations", 44th Recontres de Moriond, 2/2009 - Christopher Lindsay NaumannCEA DSM Irfu 2

Physics Motivation: Neutrinos from Astrophysical SourcesPhysics Motivation: Neutrinos from Astrophysical Sources

•TeV neutrinos by-product in cosmic accelerators:TeV neutrinos by-product in cosmic accelerators:

Gamma Ray Bursts

• “smoking gun” for hadronic acceleration

• probe for hidden sources: no magnetic deflection, (nearly) no absorption

new window to astrophysics!

supernova remnants

Active galacticnuclei (AGN)

p/A + p/ + ...

e e


Existing Neutrino TelescopesExisting Neutrino Telescopes

Lake Baikal Lake Baikal, Siberia:

• Baikal Deep Underwater Neutrino Telescope (1993+)

South Pole:

• AMANDA (1996+)

• IceCube (2005+)under construction,first km3 size detector

Mediterranean:

• ANTARES (completed summer 2008)

• R&D project NEMO, NESTOR

• no km3 sized detector in the North !

South Pole

Mediterranean


KM3NeT – a kmKM3NeT – a km33 neutrino telescope in the Mediterranean neutrino telescope in the Mediterranean

Consortium of Consortium of ~~40 laboratories from 10 European countries40 laboratories from 10 European countries

Combines Mediterranean projects ANTARES, NEMO and NESTOR Combines Mediterranean projects ANTARES, NEMO and NESTOR

neutrino astronomy on a new scaleneutrino astronomy on a new scale + earth and sea science + earth and sea science

– Design Study (2006-2009): “develop adevelop a cost-effective designdesign for the construction of a 1 km3 neutrino telescope”

– Preparatory Phase (2008-2011): “prepararationprepararation for constructionconstruction by defining the legal, financial and governance issues, as well as the pre-pre-productionproduction of the telescope componentstelescope components”

co-financed by E.U. (FP6 and FP7)


The KM3NeT siteThe KM3NeT site

ToulonToulon

Capo PasseroCapo Passero

PylosPylos

candidate sitesthree candidate sites in the

Mediterranean

depth 2500-5500 m

different water properties

decision pending

sky coverage > 2 sr

complementary to IceCube (but overlap)

Galactic centre

HESS sources

KM3NeT


KM3NeT – Design GoalsKM3NeT – Design Goals

complementary to IceCube and with complementary to IceCube and with improved physics improved physics sensitivitysensitivity

−angular resolution 0.1° above 30TeV angular resolution 0.1° above 30TeV − focus energy range 1 TeV – 1 PeVfocus energy range 1 TeV – 1 PeV−good muon background suppressiongood muon background suppression

design goals and technical options formulated in CDR www.km3net.org/CDR/CDR-KM3NeT.pdf

need O(10need O(1044) optical modules, instrumented ) optical modules, instrumented volume O(1kmvolume O(1km33) () (~~50 × ANTARES50 × ANTARES).).

physics simulation information tech.

hardware development risk assessment

deep sea infrastructure associated science

management …

ISB

N 9

78-90-6488-03

1-5


42°sea floor

interaction

Cherenkovlight from

3D PMT array

reconstruct muon (neutrino) trajectory from position and timing of hits

Neutrino Telescope: Detection PrincipleNeutrino Telescope: Detection Principle

efficiency and quality depend strongly on PMT distribution !


Geometry optimisation studiesGeometry optimisation studies

Detector optimisation: a multidimensional problem !

find detector which is…

1. optimised for physics goals

2. technically and financially feasible

3. can be built on short time scale!

− ”physics”: neutrinos, atmospheric , optical background

− “hardware”: detector characteristics, water properties

use return of experience from ANTARES, NEMO and NESTOR!

sea floor layout

type of detection units

detector site (water properties, depth)

trigger, reconstruction

readout

data flow

…


Optimisation: Possible detector layoutsOptimisation: Possible detector layouts

• square / hexagonal grids, rings, clusters

• large range of horizontal and vertical distances

−None ideal for all energies and directionsNone ideal for all energies and directions

−optimum distances optimum distances energy range, site energy range, site

optimisation ongoing !


Optimisation: Detection UnitsOptimisation: Detection Units

investigate different types of detection units:

• “strings” (1D) or “towers” (3D)

• single large or many small PMTs

• directional PMTs, hybrid photodetectors,…

multi-PMT directional PMT

large PMT

cable, multi-PMT3D tower

string, 10” PMTs

~10m (schematic)

hybrid PD

→ affect detector characteristics!

→ included in simulation


Example results: Reference detector (CDR)Example results: Reference detector (CDR)

Geometry: “string type”

• 15 x 15 strings, rectangular grid, horizontal distances 95 m

• 37 storeys, distance 15.5m

• storey: single OM with 21 3’’ PMTs

neutrino effective area (defines event rate)

~30 × ANTARES !~30 × ANTARES !

representative detector designbasis for sensitivity studies

NOT the final KM3NeT design!

O(102) m2 E ≥ 100TeV

2×10-1 m2 at 1 TeV

ANTARES

simulationkm3


Point source limits, reference detectorPoint source limits, reference detector

limits better than ANTARES and IceCube:better angular resolution and larger photocathode area

within reach of model predictions for several known CR sources !

preliminarypreliminary!

point source limits:

• source flux E-2

• background:atmospheric only

• 90 % CL

• Tmeas = 1 yearx 30


Diffuse fluxes, reference detectorDiffuse fluxes, reference detector

~ factor 10 below Waxman-Bahcall bound

reach area interesting for neutrino searches!

KM3NeT

W-B

IceCubeIceCube

ANTARESANTARES

atmospheric flux (Bartol)diffuse flux sensitivity:

• spectrum E-2

• only CC

• MC energy


Dark matter sensitivity (Dark matter sensitivity (reference detector)reference detector)

Detectability:

- Blue: ANTARES

- Green: KM3NeT

- Red: None of them

preliminary values, need for further optimisation !

Scan of mSUGRAparameter space

Focus on pointscompatible withWMAP data

significant increase over ANTARES sensitivity


Conclusions and OutlookConclusions and Outlook

• KM3NeT consortium in the process of designing a kmKM3NeT consortium in the process of designing a km33 size detector for the Mediterraneansize detector for the Mediterranean

• large number of options for layout and technology studied, large number of options for layout and technology studied, narrowing parameter space downnarrowing parameter space down

• first values for sensitivity (non-optimised)first values for sensitivity (non-optimised) Conceptual Design Report ready (April 2008)Conceptual Design Report ready (April 2008)

• Next step: Finalisation of storey and detector layoutNext step: Finalisation of storey and detector layoutTechnical Design Report (TDR) end of 2009Technical Design Report (TDR) end of 2009

• construction of working prototypesconstruction of working prototypes• Start of construction foreseen 2011Start of construction foreseen 2011

Thank you !

Documents

Status of KM3NeT (Detector Design Optimisations) Christopher Naumann, CEA Saclay – IRFU / SPP for the KM3NeT consortium 44 th Reconcontres de Moriond,