QGP France 20-23 sept 2010Sanjoy Pal Performances of the tracking Chambers of the ALICE MUON...
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QGP France 20-23 sept 2010 Sanjoy Pal Performances of the tracking Chambers of the ALICE MUON Spectrometer 1
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Transcript of QGP France 20-23 sept 2010Sanjoy Pal Performances of the tracking Chambers of the ALICE MUON...
1Sanjoy Pal QGP France 20-23 sept 2010
Performances of the tracking Chambers of the ALICE MUON Spectrometer
2Sanjoy Pal QGP France 20-23 sept 2010
ALICE muon Spectrometer
x
y
z
muon Spectrometer
Physics Goals :Studying heavy quark production via their muonic and semi-muonic decay inForward rapidity (-4 < y < -2.5)Large quarkonia acceptance down to pT 0Measurement of Quarkonia production - as a function of centrality (ZDC) - as a function of pT, rapidity
St3 , St4 and St5 Slats type
St1 and St2Quadrants type
Muon Tracking System:Five stations Two detection planes for each station.
Detection plane consists of Multi wire proportional chambers with bi-cathode pad readout: bending and non-bending. Expected Spatial resolution below 100 m in the bending plane, around 700 µm in the non-bending
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Muon Tracking System
Muon Tracking System:The total area of covers about 100 m2
Total number of readout pads about 1 million
Gas Mixure : Ar + CO2 (20%)High Voltage : 1650 VoltWire diameter : 20 µmWire pitch : 2 mm for St1
: 2.5 mm for St 2,3,4 & 5Anode cathode gap : 2 mm for St1
: 2.5 mm for St 2,3,4 & 5
Pad width y direction for Bending Cathode 4 mm for St1 5 mm for St 2,3,4 & 5 Pad width x direction for Non-bending Cathode 6 mm for St1 7.5 mm for St 2,3,4 & 5
The chamber thickness : 0.03 X0
Muon Dipole Magnet (Bx) :
B=0.7 T, ∫Bdl ~ 3 Tm
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Readout buspatches configuration for the NonBending plane
in red buspatchs which are present in configurationIn white buspatchs which are removed from configuration
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Readout buspatches configuration for the Bending plane
5% of the Read out Channel are removed form configuration
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Pedestal Bending (max 500 ADC Channel)
in black MANU`s which are also dead
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Pedestal NonBending (max 500 ADC Channel)
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Noise Bending (max 5 ADC Channel)
1 ADC Ch ~ 1000 e
Noise below 3 ADC Ch for most of the read out Channel and average around 1.5 Ch which is very good
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Noise Non Bending (max 5 ADC Channel)
Noise is higher compare to bending plane but it is less critical
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Zero-Suppression
QGP France 20-23 sept 2010
The pedestal and noise per readout channel give threshold for 0-suppression : critical parameter !
• Mean and sigma values of pedestals for each readout channel are calculated by DA over 400 event //
===========================================================================
// NEW File calculated by makeped//
===========================================================================
// * Statistics : 400// * # of MANUS : // * # of channels : ////---------------------------------------------------------------------------//format ://---------------------------------------------------------------------------// BUS_PATCH MANU_ADDR CHANNEL MEAN SIGMA//---------------------------------------------------------------------------1 4 0 112.572 0.8699521 4 1 207.938 0.8911541 4 2 212.385 1.069011 4 3 242.233 0.9770931 4 4 302.468 1.026151 4 5 221.775 0.9188991 4 6 263.75 1.008711 4 7 185.86 0.9840731 4 8 241.141 0.9439911 4 9 246.949 0.919999• 4 10 209.31 0.89883
…
Flat ASCII file
Zero-Suppression is performed by FEE (MARC).Pedestal and noise
distribution for one
plane of a quadrant
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High Voltage configuration
1400 V
Nominal HV = 1650 volt
1500 V
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Total Cluster charge distributions in pp run 2010
Station 1 have relatively High gain Station 2 have relatively low gain compare to Station 3, 4 & 5
QGP France 20-23 sept 2010
Absolute values of gain are not important for position resolution calculation
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No of pad hits in the B plane involved in a cluster for each chamber
QGP France 20-23 sept 2010
3 Pad hit in bending direction is needed for nominal position resolution
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No of pad hits in the NB plane involved in a cluster for each chamber
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Charge correlation between two cathodes
QGP France 20-23 sept 2010
Station 1Station 2
Station 3 Station 4 Station 5
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Occupancy Bending (max 0.01)
Mean Occupancy ~ 0.002
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Occupancy NonBending (max 0.01)
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Condition to reconstruct a track :one hit among chambers 1 & 2.one hit among chambers 3 & 4.one hit among chambers 5 & 6.three hits among chambers 7, 8, 9 & 10.Total tracking efficiency for LHC10e : Total = 93.7 ± 0.9 %
QGP France 20-23 sept 2010
Chamber Efficiency
19Sanjoy Pal QGP France 20-23 sept 2010
Summary
• We have a quite stable read-out configuration with a busy time most often less than 500 μs ; baseline is 330 μs.• We have a quite stable HV configuration.• Excellent behavior of all the Muon Chambers was
achieved during pp run-2010.• Tracking efficiency ~95%• Ready for HI data taking.
