The ANTARES Project

Sino-French workshop on the Dark Universe

Stephanie Escoffier

Centre de Physique des Particules de MarseilleOn behalf of the ANTARES collaboration

Marseille, September 19-23, 2005

Sino-French workshop on the Dark Universe

Neutrino Astronomy

Galactic and Extra-galactic Point Sources of High Energy Neutrinos

Pulsar

Young Super Nova Remnants

Microquasar

Galactic Centre(visibilty 67% of the day)

Active Galactic Nuclei

Gamma Ray Bursts

Neutralino annihilationsin the Sun, in the Earth, in the Galactic Center

Dark Matter searches

Sino-French workshop on the Dark Universe

Site Location: La Seyne sur Mer

Water Properties

transparency: abs ~ 608 m (blue) abs ~ 262 m (UV)

light scattering : eff ~ 300 m (blue) eff ~ 100 m (UV)

cos 1

sc

eff

For > 90º the loss in transmissio

n is < 1.5%

in 1 year.

Biofouling

= 0°

= 90°

42º50’N, 6º10’E

Sino-French workshop on the Dark Universe

43°2500 mdepth

Cherenkov light from induced by interaction detected by 3D PMT array Time & position of hits allow the reconstruction of the (~ ) trajectory

interaction

Neutrino detection

Sino-French workshop on the Dark Universe

Expected Angular Resolution

Dominated byreconstruction

Dominated by kinematic

angle

Reconstruction resolution limited only by phototube TTS and light diffusion in water

true

rec

Simulated events, including:

• TTS

• scattering of light

• light absorption

• light background

Sino-French workshop on the Dark Universe

Point-like sources: expected sensitivity

After 1 year, Antares can improve

limit for Southern hemisphere…or discover something !

90%

c.l

. M

uon

flu

x l

imit

s (c

m-2

s-1

)

Declination (degrees)

AMANDA B-10 130 daysE>10 GeV, angular resolution ~ 3.9 deg (2003).

MACRO 1388 events in ~6 y <E> > 1.5 GeV, angular resolution ~ 0.5 deg

SK 2369 upward-going stopping and through-going muons in 4.6 y, <E> > 3 GeV, angular resolution of about 2° (ICRC 2003).

AMANDA II sensitivity197 days (2004)

southern sky northern sky

ANTARES sensitivity 1 yr

E-2 neutrino spectrum

AMANDA II

Sino-French workshop on the Dark Universe

Detector Geometry

70 m

12 lines (900 PMTs) 25 storeys / line 3 PMTs/storey

350 m

100 m

14.5 m

Junctionbox

Readout cables

40 km toshore

2500 m

storey

Horizontal layout

Sino-French workshop on the Dark Universe

Hydrophone RX

Cage (magnetic shield)

Local Control Module

Optical Beacons for timing calibration (blue

LEDs)

Line storey elements

10” PMT in the glass sphere

Sino-French workshop on the Dark Universe

The excellent angular resolution of ANTARES relies on the global timing resolution and on an accurate knowledge in real time of the OMs positions

• In-situ calibration systems:– Clock calibration system– LEDs in Optical Modules– Optical Beacons– Laser Beacons

Strings

Light sources

Light shells

Optical modules

• Timing calibration goals of ANTARES: ~1 ms in absolute timing (internal clock w.r.t. UTC) ≤ 0.5 ns in relative timing (between OMs)

ANTARES Time Calibration System

Sino-French workshop on the Dark Universe

test of deployment and mechanical structure of a full line (23 storeys)

equipped with water leak sensors and instruments for attenuation measurements

Recovery showed:

no water leaks in electronic containers

optical transmission losses due to an interface problem between EMC penetrators and the LCM cylinder solution proposed, under validation

2005: Line O

Sino-French workshop on the Dark Universe

2005: the MILOM

Led Beacon

Led Beacon

Laser Beacon

50 m

14.5 m

100 m

1 OM

3 OMs

ADCP

Sound Velocimeter

CT (Conductivit

y Temperature

)

CSTAR (Light Transmission

meter)

Acoustic Positioning Module (Rx)

Acoustic Positioning

Module (RxTx)

Buoy

Acoustic positioning system Receiver at 1 storey Transceiver (transmitter +

receiver) at anchor

Instrumentation components current profiler (ADCP) sound velocimeter water properties (CSTAR, CT)

Optical components Equipped with final electronics 3 + 1 optical modules at two storeys

Time calibration system Two LED beacons at two storeys Laser Beacon attached to anchor

Deployed in March, connected in April, still taking data

Sino-French workshop on the Dark Universe

MILOM Clock Calibration

Slope due to an increase of the average temperature in the on-shore cable

~1 ns

JB

MEOC4o km

Sino-French workshop on the Dark Universe

Optical Beacons Calibration

Time difference between signals

between 2 OMs in a storey

Time difference between the OMs and the internal PMT of the LED beacon (low TTS)

14

.5

m

Mean of the distribution of time difference of hits on 2 adjacent OMs stability of

calibrations

Sino-French workshop on the Dark Universe

Resolution of ~3 cm

on a distance measurement

of ~84 m

Acoustic Positioning SystemANTARES required precision

on 3D position of the OMs is ~10

cm.

Sound velocimeter

Sino-French workshop on the Dark Universe

Measurement of the water current profile using the Doppler effect

ADCP Measurements

04590

135180225270

315360

15 Apr 29 Apr 13 May 27 May 10 Jun 24 Jun 08 Jul 22 Jul 05 Aug 19 Aug

Date

Dir

ecti

on (

°)

0.00

0.05

0.10

0.15

0.20

Spee

d (m

.s-1

)

Current directionCurrent speed

Vaverage = .093 m s-1

Preferred directions: ~ West East

Sino-French workshop on the Dark Universe

Measurement of water temperature

Temperature measured by CT-Seabird

13.16

13.18

13.20

13.22

13.24

13.26

13.28

13.30

13 Apr 27 Apr 11 May 25 May 08 Jun 22 Jun 06 Jul 20 Jul 03 Aug

Date

Tem

pera

ture

(o C

)

JB

Sino-French workshop on the Dark Universe

Baseline and Burst Fraction

The burst fraction is the time ratio during which the counting rate exceeds the baseline by more than 20%

Sino-French workshop on the Dark Universe

Conclusions

• The MILOM has been a big step forward in understanding the behaviour of all the ANTARES devices.

• Timing calibration systems have been successfully tested in the sea.

• Line 1 construction has started and is expected to be running in January 2006.

• The full 12-string detector operation can be expected in 2007.