CRIS 2008 - Cosmic Ray International Seminar Origin, Mass Composition and Acceleration Mechanisms of UHECRs Malfa, Salina Island, Eolian Islands, Italy, September 15 - 19 , 2008 Raffaello D’Alessandro Università & INFN - Firenze 1 CRIS 2008 - Malfa, Salina Island, September 15 - 19 , 2008
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CRIS 2008 - Cosmic Ray International Seminar Origin, Mass Composition and Acceleration Mechanisms of UHECRs Malfa, Salina Island, Eolian Islands, Italy,
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CRIS 2008 - Cosmic Ray International Seminar
Origin, Mass Composition and Acceleration Mechanisms of UHECRs
Malfa, Salina Island,Eolian Islands, Italy, September 15 - 19 ,
2008
Raffaello D’Alessandro Università & INFN - Firenze 1
JAPAN:STE Laboratory Nagoya University:K.Fukui,Y.Itow, T.Mase, K.Masuda,Y.Matsubara, H.Menjo,T.Sako, K.Taki, H. WatanabeWaseda University: K. Kasahara, M. Mizuishi, Y.Shimizu, S.ToriiKonan University: Y.MurakiKanagawa University Yokohama: T.TamuraShibaura Institute of Technology: K. Yoshida
Raffaello D’Alessandro Università & INFN - Firenze
In this forward region the highest energy In this forward region the highest energy available measurements oft he available measurements oft he 00 cross cross
section were done by UA7 (E=10section were done by UA7 (E=101414 eV, y= eV, y= 5÷7)5÷7)
LHCLHC
TevatronTevatron
A 100 PeV fixed-target interaction A 100 PeV fixed-target interaction with air has the cm energy of a with air has the cm energy of a pp collision at the LHCpp collision at the LHC
AUGERAUGER
Cosmic ray spectrumCosmic ray spectrum
LHCf first proposed using LHCf first proposed using LHC, the highest energy LHC, the highest energy accelerator availableaccelerator available(14 TeV E(14 TeV ECMCM equiv. to equiv. to EElablab=10=101717 eV ) eV )
to calibrate MC simulation to calibrate MC simulation codecode
Raffaello D’Alessandro Università & INFN - Firenze
Detectors installed in the TAN Detectors installed in the TAN region, 140 m away from the region, 140 m away from the Interaction Point, in front of Interaction Point, in front of luminosity monitors.luminosity monitors.
Raffaello D’Alessandro Università & INFN - Firenze
Detectors should measure energy Detectors should measure energy and position of and position of from from 00 decays decays
e.m. calorimeters with position e.m. calorimeters with position sensitive layerssensitive layers
INTERACTION POINTINTERACTION POINT
IP1 (ATLAS)IP1 (ATLAS)
Beam Beam lineline
Detector IIDetector II
TungstenTungsten
ScintillatorScintillator
Silicon Silicon stripsstrips
Detector IDetector I
TungstenTungsten
ScintillatorScintillator
Scintillating fibersScintillating fibers
140 m140 m 140 m140 m
Two independent detectors on both side of IP1Two independent detectors on both side of IP1 RedundancyRedundancy Background rejection (especially beam-gas)Background rejection (especially beam-gas)
Raffaello D’Alessandro Università & INFN - Firenze
2 towers 24 cm long stacked on their edges and 2 towers 24 cm long stacked on their edges and offset from one anotheroffset from one anotherLower: 2.5 cm x 2.5 cmLower: 2.5 cm x 2.5 cmUpper: 3.2 cm x 3.2 cmUpper: 3.2 cm x 3.2 cmAbsorberAbsorber
22 tungsten layers 22 tungsten layers 7mm – 14 mm thick 7mm – 14 mm thick
(W: X(W: X00 = 3.5mm, R = 3.5mm, RMM = = 9mm)9mm)
16 scintillator layers 16 scintillator layers (3 mm thick) (3 mm thick)
Trigger and energy Trigger and energy profile profile
measurementsmeasurements
4 pairs of silicon microstrip layers4 pairs of silicon microstrip layers (6, 10, 30, 42 (6, 10, 30, 42 XX00) for tracking ) for tracking purpose (X and Y directions)purpose (X and Y directions)
Raffaello D’Alessandro Università & INFN - Firenze
Installation performed in two phases:Installation performed in two phases:1.1. Pre-Installation (Jan/Apr 2007)Pre-Installation (Jan/Apr 2007) Baking out of the beam pipe (200 Baking out of the beam pipe (200
°C)°C)2.2. Final Installation (Jan 2008)Final Installation (Jan 2008)
Raffaello D’Alessandro Università & INFN - Firenze
1. Single photon spectrum2. 0 fully reconstructed (1 in each tower)
0 reconstruction is an important tool for energy calibration (0 mass constraint)
Basic concept: Minimum 2 towers (0 reconstruction)Smallest tower on the beam (multiple hits)Dimension of the tower Moliere radiusMaximum acceptance (given the LHC constraints)
Simulation is used to understand the physics performances
Beam tests in 2004, 2006 and 2007 Energy resolutionSpatial resolution of the tracking part
DPMJET3QGSJETQGSJETIISIBYLL
Used as ExamplesOf the models
Raffaello D’Alessandro Università & INFN - Firenze
106 generated LHC interactions 1 minute exposure@1029 cm-2s-1 luminosity Discrimination between various models is feasible
Quantitative Quantitative discrimination with the discrimination with the help of a properly help of a properly defined defined 22 discriminating discriminating variable based on the variable based on the spectrum shape spectrum shape (see TDR for details)(see TDR for details)
Raffaello D’Alessandro Università & INFN - Firenze
•Phase-I• 900 GeV collision before ramping in 2008 (hope in a week from now!)• 10 TeV run in 2008 during the LHC commissioning (low luminosity)•14 TeV run in 2009 during commissioning •Remove LHCf when luminosity reaches 1030 cm-2s-1 for radiation damage reasons
•Phase-II•Re-install the detector at the next opportunity of low luminosity run •Dedicated runs (crossing angle, etc.)
•Phase-III•Future extension for p-A, A-A run with upgraded detectors are under study
Beam parameter
Value
# of bunches ≤ 43
Bunch separation
> 2 sec
Crossing angle
0 rad140 rad downward
Luminosity per bunch
< 2 x 1028 cm-2s-1
Luminosity < 1030 cm-2s-1
Bunch intensity
4x1010 ppb (*=18m)1x1010 ppb (*= 1m)
Raffaello D’Alessandro Università & INFN - Firenze