Experimental cosmic ray physics in the 1017 1019 eV region

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Experimental cosmic ray physics in the 1017
1019 eV region

• Associated detectors

Federico Suarez Lab. Tandar, Comisión Nacional de
Energía Atómica January 19th, 2009. SILAFAE 2009
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Pierre Auger Observatory (finished)

• - Location Malargüe, Argentina
• Altitude 1400 m (osl)
• Area 3000 km2

• UHECR
• Measure spectrum, arrival direction, and chemical
  composition above 1018eV
• Low rate 1 per km2 each 100 years
• PAO
• Area 3000km2 gt 30 UHE event per year
• 1600 surface detectors (1.5km spacing) 24
  florescence telescopes
• Hybrid technique
• SD (Surface Detectors) high statistics, good for
  angular reconstruction
• FD (Fluorescence Detectors) good for energy
  estimation (proportional to e.m. component of the
  EAS)

3
PAO upgrades
Auger hybrid E gt 1018 eV Upgrades (AMIGA-HEAT)
E gt 1017 eV

• Objectives
• Study 2nd knee and ankle
• Better mass-composition analysis

Primary particle
knee 1015,5 eV Ankle 1018,5 eV GZK -
cut-off 6x1019 eV
Particles cascade Extensive air shower
AMIGA Auger Muons and Infill for the Ground
Array HEAT High Elevation Auger Telescopes
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Simulations of mass composition
Proton
Iron

• 50 more muons expected for Irons
• Deeper Xmax for Protons
• No systematic errors expected from reconstructions

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AMIGA project
Auger spacing 1.5km

• AMIGA (Auger Muons and Infill for the Ground
  Array)
• Double graded SD infill
• Buried Muon counters

750m spacing
433m spacing
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AMIGA Surface Detectors Infill
Event hitting a Unitary Cell
- Unitary cell Array of 7 detectors
35/61 SD commissioned
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Muon counter design
64 channels PMT
Electronics
WLS fiber
1 prototype module of 64 strips

• Underground detector
• 4 modules
• Detection area 30m2

muon
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Muon counting
No pile-up of pe-
muon
WLS fiber
Scintillator

• Threshold below SPE level
• If every pe- counted as muon then Over-counting
• Over-counting due to PMT X-talk, dark-pulse rate,
  etc.
• Then, Muon discrimination from more than 2 pe-
• Pulses identification with high sampling rate

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Electronic boards
Analog. Digital, Power Distributor
Boards prototyping finished
DATA TRANSFER Successfully tested µ-controller
kit, digital board, and remote SBC via CAN bus
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AMIGA Analog Front EndTest Results,
Photoelectron Trend
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Telecoms layout
AMIGA comms box
Auger radio removed (and re-used elsewhere)
-WiFi prototype currently running -Production
comms based on IEEE 802.15.4
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Muon counters manufacturing
Strip-Case Gluing
Fly Cutter
New lab built with central vacuum system
monocrystal diamond fly cutter tool , one cuts,
the other polishes (not to scale)
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Muon counter design (each module)
Pipe for electronic cables and power supply
Electronic from center of the counter Bubble
enclosure for electronics (335.2 mm high)?
Support for service pipe
U profiles to avoid deformation
O-ring to seal the electronics
Counter dimensions 1350 mm wide and 4840 mm long
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Buried prototype in Tandar lab.
Buried 3m underground
Access tunnel
Amplitude
Charge
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Muon counters testing
Sliding door to Remove counters
137Cs source lodging Al scanner frame
Video motion is 36 faster than in real life
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Modules transportation
Finite elements studies
Scale in meters deformation less than 1cm
Crosscheck test with simulation and experimental
with a 2 m prototype OK!
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PMT to fibers alignment
40 of events have more than 20 energy change
Spikes to align PMT with optical connector

• Digital camera Lu105M 1280x1024 pixels
• Objective, macro zoom f18-108 mm

4 PMT alignment dots
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PMT testing
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Costs and chronogram
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Conclusion
Auger will be uniquely positioned to study cosmic
rays with E gt 1017 eV with an ultimate detector
system composed of extended field of view
fluorescence telescopes, surface detectors, and
buried muon counters, all working with unitary
efficiency with no composition biases.