1. QGP France 20-23 sept 2010Sanjoy Pal Performances of the tracking Chambers of the ALICE MUON Spectrometer 1

2. QGP France 20-23 sept 2010Sanjoy Pal ALICE muon Spectrometer x y z muon Spectrometer 2 Physics Goals : Studying heavy quark production via their muonic and semi-muonic decay in Forward rapidity (-4 < y < -2.5) Large quarkonia acceptance down to p T  0 Measurement of Quarkonia production - as a function of centrality (ZDC) - as a function of p T, rapidity St3, St4 and St5 Slats type St1 and St2 St1 and St2 Quadrants 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

3. QGP France 20-23 sept 2010Sanjoy Pal 3 Muon Tracking System Muon Tracking System: The total area of covers about 100 m 2 Total number of readout pads about 1 million Gas Mixure : Ar + CO2 (20%) High Voltage : 1650 Volt Wire diameter : 20 µm Wire pitch : 2 mm for St1 : 2.5 mm for St 2,3,4 & 5 Anode 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

4. QGP France 20-23 sept 2010 4 Sanjoy Pal Readout buspatches configuration for the NonBending plane in red buspatchs which are present in configuration In white buspatchs which are removed from configuration

5. QGP France 20-23 sept 2010 5 Sanjoy Pal Readout buspatches configuration for the Bending plane 5% of the Read out Channel are removed form configuration

6. QGP France 20-23 sept 2010 6 Sanjoy Pal Pedestal Bending (max 500 ADC Channel) in black MANU`s which are also dead

7. QGP France 20-23 sept 2010 7 Sanjoy Pal Pedestal NonBending (max 500 ADC Channel)

8. QGP France 20-23 sept 2010 8 Sanjoy Pal 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

9. QGP France 20-23 sept 2010 9 Sanjoy Pal Noise Non Bending (max 5 ADC Channel) Noise is higher compare to bending plane but it is less critical

10. Zero-Suppression 10 QGP France 20-23 sept 2010 Sanjoy Pal 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 //--------------------------------------------------------------------------- 140112.5720.869952 141207.9380.891154 142212.3851.06901 143242.2330.977093 144302.4681.02615 145221.7750.918899 146263.751.00871 147185.860.984073 148241.1410.943991 149246.9490.919999 410209.310.89883 … Flat ASCII file Zero-Suppression is performed by FEE (MARC). Pedestal and noise distribution for one plane of a quadrant

11. QGP France 20-23 sept 2010 11 Sanjoy Pal High Voltage configuration 1400 V Nominal HV = 1650 volt 1500 V

12. 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 12 Sanjoy Pal Absolute values of gain are not important for position resolution calculation

13. No of pad hits in the B plane involved in a cluster for each chamber QGP France 20-23 sept 2010 13 Sanjoy Pal 3 Pad hit in bending direction is needed for nominal position resolution

14. QGP France 20-23 sept 2010 14 Sanjoy Pal No of pad hits in the NB plane involved in a cluster for each chamber

15. Charge correlation between two cathodes QGP France 20-23 sept 2010 15 Sanjoy Pal Station 1 Station 2 Station 3Station 4Station 5

16. QGP France 20-23 sept 2010Sanjoy Pal 16 Occupancy Bending (max 0.01) Mean Occupancy ~ 0.002

17. QGP France 20-23 sept 2010 17 Sanjoy Pal Occupancy NonBending (max 0.01)

18. 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 % 18 QGP France 20-23 sept 2010Sanjoy Pal Chamber Efficiency

19. QGP France 20-23 sept 2010Sanjoy Pal 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. 19