AUGER Experiment Status and Performances

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AUGER Experiment Status and Performances

• F. Arneodo - Gran Sasso Laboratories
• On behalf of the AUGER collaboration

Rencontres de Moriond 2005 Very High Energy
Phenomena in the Universe. La Thuile, Italy
(March 12-19, 2005)
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Pierre Auger Collaboration
16 Countries 50 Institutions 350 Scientists
Italy Argentina Czech Republic
Australia France Brazil Germany
Bolivia Greece
Mexico Poland USA Slovenia
Vietnam Spain United Kingdom
Associate Countries
Spokesperson Prof. Alan Watson
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UHE Cosmic Rays
Eo gt1020 eV 1 part. / (km2 century sr) ? 102
103 km2 collecting areas
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Required to solve EHECR-Puzzle
Better understanding of Syst. Errors Better
Resolution in Energy and Direction Much
more Statistics

• Hybrid Approach
• Independent EAS-observation techniques
  Shower-by-Shower in one Experiment
• Much larger Experiment

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Southern Site
Pampa Amarilla Province of Mendoza 3000 km2, 875
g/cm2, 1400 m
Surface Array 1600 Water Tanks 1.5 km
spacing 3000 km2
Lat. 35.5 south
Fluorescence Detectors 4 Sites (Eyes) 6
Telescopes per site (180 x 30)
70 km
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Water Tank in the Pampa
Communication antenna
GPS antenna
Electronics enclosure 40 MHz FADC, local
triggers, 10 Watts
Solar Panel
three 9 PMTs
Plastic tank with 12 tons of water
Battery box
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Installation Chain
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View of Los LeonesFluorescence Site
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Six Telescopes viewing 30x30 each
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Schmidt Telescope using 11 m2 mirrors
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Aligned Water Tanksas seen from Los Leones
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Status of the SD (March 16th 2005) 685 tanks
taking data
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Los Leones (fully operational)
Coihueco (fully operational)
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Calibration
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SD Calibration by Single Muon Triggers
Agreement with GEANT4 Simulation up to 10 ? VEM
(Vertical Equivalent Muons). VEM 100 PE
/PMT Huge Statistics! Systematic error 5
Sum
PMT 1
VEM Peak
Local EM Shower
PMT 2
PMT 3
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SD calibration monitoring
Base-Temperature vs Time
Single tank response
single muons
Noise
Signal-Height vs Time
Signal-Height vs Base-Temp
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Huge Statistics! Systematic error 5
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FD Calibration
Absolute End to End Calibration
N Photons at diaphragm ? FADC counts
A Drum device installed at the aperture uniformly
illuminates the camera with light from a
calibrated source (1/month)
Mirror
Calibrated light source
Camera
Diffusely reflective drum
Drum from outside telescope building
Relative UV LED optical fibers (1/night)

• Alternative techniques for cross checks
• Scattered light from laser beam
• Calibr. light source flown on balloon

All agreed within 10 for the EA
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Atmospheric Monitoring

• LIDAR at each eye
• cloud monitors at each eye
• central laser facility
• regular balloon flights

steerable LIDAR facilities located at each FD
eye
Central laser facility (fibre linked to tank)
LIDAR at each FD building

• light attenuation length
• Aerosol concentration

Balloon probes ? (T,p)-profiles
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PerformancedemonstratedbyFirst Preliminary Data
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I
II

III
T31200/day T4600/day
IV
n.b. When a T3 occurs (either SD or FD) all the
stations are polled and are acquired if they
passed a T1 within a certain time window
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Vertical (q35o) Inclined (q72o)
35 tanks
14 tanks
14 km
Energy (6-7) 10 19 eV
13 km
7 km
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Young Old Shower
young shower
old shower
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Neutrino Sensitivities (per site)
Expected no. per year
?e and ?? Sensitivity
?? Sensitivity
High
DIS
None
?? Limit (E-2) for 5 years
X. Bertou et. al. Astropart. Phys. 17 (2002) 183
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A Big One 1020 eV, q 60
34 tanks
60
8 km
(m)
14 km
propagation time of 40 µs
Lateral Distribution Function
1020eV
1?1020eV
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EAS as seen by FD-cameras
EAS as seen by FD-cameras
Two-Mirror event
Only pixels with 40 pe/100 ns are shown (10 MHz
FADC ? 4 g/cm2 12 bit resol., 15 bit dynamic
range) Pixel-size 1.5 light spot 0.65
(90) 1019 eV events trigger up to 30 km
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Energy Reconstruction
Integral of Longitudinal Shower Profile ? Energy
4.8 Photons / m / electron ( 0.5 of dE/dx)
preliminary
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A Stereo Hybrid q 70
70
Coihueco Fluores. Telescope
global view
37 km
Lateral Distribution Function
81019eV
24km
Los Leones Fluores. Telescope
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A stereo hybrid q 70
37 km
24km
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37 km
A stereo hybrid q 70
24km
IR camerano clouds seen in FoV of Coihueco
x
x
x
IR camerano clouds seen in FoV of Los Leones
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A stereo hybrid q 70
Shower Profile
71019eV
(SD 81019eV)
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Event-by-Event FD vs SD
using hybrid geometries
Pre-Preliminary
Not yet precise, but good correlation
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Some numbers data taking from Jan. 2004 SD
number of tanks in operation 685 fully
efficient above 3.1018 eV number of events
120,000 reconstructed ( gt 3fold, gt1018 eV)
16,500 at present 600 events/day FD number
of sites in operation 2 SDFD number of hybrids
1750 350 golden
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CONCLUSIONS

• Auger construction in rapid progress in south
  Physics data taking since January 2004
• Stable operation, excellent performance
• Hybrid approach is a great advantage! (see next
  talk!)
• Auger North proposal in progress

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