the lhcf detectors: zero degree calorimeters at lhc for cosmic ray physics
DESCRIPTION
The LHCf detectors: zero degree calorimeters at LHC for cosmic ray physics. Tsuyoshi Mase for the LHCf collaboration Solar-Terrestrial Environment Laboratory, Nagoya University. Outline. Motivation of the LHCf experiment High energy cosmic ray problem hadron interaction model - PowerPoint PPT PresentationTRANSCRIPT
The LHCf detectors: zero degree calorimeters at LHC for cosmic ray physics
Tsuyoshi Mase
for the LHCf collaboration
Solar-Terrestrial Environment Laboratory,
Nagoya University
12 Mar. 2009 TIPP09 T.Mase 2
Outline
Motivation of the LHCf experimentHigh energy cosmic ray problem
hadron interaction model
LHCf detectorLocation
Discrimination the hadron interaction models
Design
Performance (SPS beam test and simulation)
Conclusion
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Energy spectrum of cosmic rays
Engel, Nuclear Phys. B (Proc. Suppl.) 151 (2006) 437-461
Knee; acceleration limit of galactic CRs?
GZK cutoff; Propagation limit due to CMB
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Cosmic ray composition by Auger
Xmax favors heavy primary
Anisotropy favors light primary (if accept AGN correlation)
interpretation strongly depends on the hadron interaction model
Confirmation of the various models using the LHC is important key for the cosmic ray physics.
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LHC accelerator
The 14TeV center of momentum energy of the LHC will push the laboratory equivalent collision energy up to 10^17eV.
ATLAS / LHCfLHCb
CMS / TOTEM
ALICE
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The LHCf collaborator
K.Fukui, Y.Itow, T.Mase, K.Masuda, Y.Matsubara, H.Menjo, T.Sako, K.Taki
Solar-Terrestrial Environment Laboratory, Nagoya University, JapanK.Yoshida Shibaura Institute of Technology, JapanK.Kasahara, M.Mizuishi, S.Torii
Waseda University, JapanT.Tamura Kanagawa University, JapanY.Muraki Konan UniversityY.Shimizu ICRC, University of Tokyo, JapanM.Haguenauer Ecole Polytechnique, FranceW.C.Turner LBNL, Berkeley, USAO.Adriani, L.Bonechi, M.Bongi, R.D’Alessandro, M.Grandi, P.Papini, S.Ricciarini, G.Castellini, A. Viciani
INFN, Univ. di Firenze, ItalyA.Tricomi INFN, Univ. di Catania, Italy J.Velasco, A.Faus IFIC, Centro Mixto CSIC-UVEG, SpainD.Macina, A-L.Perrot CERN, Switzerland
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Location of LHCf
140mLHCfDetectors installed in the TAN region, 140m away from the Interaction Point.
Both side of I.P. (Arm1 and Arm2)
LHCf covers pseudo-rapidity > 8.4
I.P.
90cm
140m
Arm1 Arm2
neutral particle absorber
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Model dependence in LHCf
Model Discrimination by Gamma, Neutron and 0
Gamma Spectrum
expected spectra using some hadron interaction models
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LHCf Detector1 (Arm1)
16 scintillator layers (3 mm thick)
Trigger and energy profile measurements
Absorber
22 tungsten layers 7mm – 14 mm thick
(W: X0 = 3.5mm, RM = 9mm)
4 pairs of scintillating fiber layers for tracking purpose (6, 10, 32, 38 r.l.)
Energy
Impact pointImpact point
2 towers 24 cm long stacked vertically with 5 mm gap
Lower: 2 cm x 2 cm area
Upper: 4 cm x 4 cm area
44 radiation length
1.7 interaction length
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LHCf Detector2 (Arm2)
4 pairs of silicon microstrip layers (6, 12, 30, 42 r.l.) for tracking purpose (X and Y directions)
We used LHC styleelectronics and readout
16 scintillator layers (3 mm thick)
Trigger and energy profile measurements
Absorber22 tungsten layers 7mm – 14 mm thick (2-4 r.l.)
(W: X0 = 3.5mm, RM = 9mm)
2 towers 24 cm long stacked on their edges and offset from one another
Lower: 2.5 cm x 2.5 cm
Upper: 3.2 cm x 3.2 cm
Energy
Impact point
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Double arm detectors
Arm#2 DetectorArm#2 DetectorArm#1 DetectorArm#1 Detector 90mm90mm290mm290mm
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Compact calorimeter and shower leakage correction
Compact two tower calorimeterneed for science
fit the limit of TAN
avoid multi-hit
reconstruct 0 invariant massThe 0 mass can be reconstructed in the invariant mass distribution of two gamma -rays, one each hitting the two tower calorimeters of Arm1 or Arm2.
Shower leakage occursThe fraction of shower leakage is only a function of the position and independent of the energy
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SPS beam test
2007 Aug. 24 - Sep.11
Aim for SPS beam test
Calibration the performanceEnergy Calibration
Energy Resolution
Position Resolution
particle ID
Silicon Tracker
LHCf Detector
Beam Pipe
electron 50, 100, 150, 180, 200GeV/c
muon 150GeV/c
proton 150, 350GeV/c
ADAMO (silicon tracker)
LHCf Detector
Trigger scintillator
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Energy Resolution
SPS beam test resultand simulation
Simulation at the LHC condition
L.G. = Low PMT Gain
H.G. = High PMT Gain
Summing up the signal in all the layers, the energy resolution is defined as root-mean-square of the distribution.
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Position Resolution (SciFi : Arm1)200 GeV electrons
SPS beam test result
Simulation at the LHC condition
The center determined by the SciFi is compared with the incident particle position estimated by ADAMO.
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Position Resolution (Silicon : Arm2)
200 GeV electrons
SPS beam test result
• 64mm x 64mm total surface area
• 285m thick n-type wafer
• A sequence of 768 p+ microstrips with 80mm pitch
This analysis was done using ADAMO for the reconstruction of the trajectory of each particle hitting the calorimeter.
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0 reconstruction (1)
9.15 m
gamma350 GeV Proton beam
Carbon target (3 cm)in the slot used for beam monitor Arm1
Not in scale!
EEgammagamma=18GeV=18GeV
Shower Profile @ First SciFi Layer Shower Profile @ First SciFi Layer Calorimeters Calorimeters
20mm20mm
XX
40mm40mm
XX YY
YYEEgammagamma=46GeV=46GeV
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0 reconstruction (2)
250 0 events triggered (in a quite big background)The background is caused by uncorrelated pairs those accidentally hit the two
calorimeters simultaneously. The background distribution was evaluated by shifting the events in the two c
alorimeters so that any correlated pairs disappear.
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Radiation test
The LHCf detectors will be exposed to a considerable amount of ionizing radiation
Using 290MeV/n Carbon beam and 100TBq 60Co gamma ray
100Gy
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LHCf Operation
LHCf operationLuminosity < 1030 cm-2 s-1
107 inelastic collision
3 days operation
The decrease of the light output is not large for doses of interest for LHCf
The laser calibration system can correct
The manipulators move the detectors to the safe position
100Gy
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Conclusion
LHCf will set a crucial calibration point at 1017eV for the hadron interaction models
The LHCf detectors are sampling and imaging calorimeterslocate both side of the IP1 (Arm1 and Arm2)
made of plastic scintillators interleaved with tungsten converters
correct the shower leakage from the calorimeter
Performance was evaluated by SPS and simulationenergy resolution is 5% above 100GeV gamma-ray
position resolution is 150um@Arm1, 50um@Arm2
reconstruct 0 mass
Radiation damage is negligible
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