Update on RICH Upgrade Simulations
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Transcript of Update on RICH Upgrade Simulations
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Update on RICH Upgrade Simulations
S.Easo,16-10-2012
RICH Upgrade meeting
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Outline
• Feasibility of the two-RICH option for upgrade.
• Last meeting: Results from using current optics / ‘modified optics’ for RICH1
‘Modified optics’ suffered PID performance loss due to acceptance effects although it reduced the peak occupancy by 50%.
• This presentation:
Further modifications to the RICH1 optics to avoid acceptance effects
Comparison of PID performances
Plans
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Optics Modifications
• Spherical mirror ROC= 2710 3800 mm (same as version2)
• Spherical mirror tilt = 240 mrad (current optics ~ 315 mrad, version2 ~ 200 mrad)
• Flat mirror: mirror segment sizes increased by 30%, but kept the same location for edge nearest to the beampipe as in version2.
• Photodetector planes tilted accordingly.
Photon: angle of incidence on PMT plane.
Mean=38 mrad
• PMT modules 5 rows7 rows in each panel of RICH1.
Optics-Version3
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RICH1 Optics
Optics-Version3
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RICH1 – Optics verifications
Optics-Version3
Particle Gun at 280 310 mrad
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Optics-Version3Particle gun at 25 35 mrad
RICH1 Optics Verifications
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RICH1 Optics verifications
Cherenkov angle reconstructed in Particle gun events
Width=0.72 mrad
Optics Version3
RICH1 yieldMean=36
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Datasets and simulation options
• Gauss v42r1, Brunel v44r0
Luminosity cm-2 s-1
Beam Energy (TeV)
Spill Over Photo-Detector
Lumi2-S 2 x 10 32 3.5 No PMT-SBA
Lumi20-S 20 x 10 32 7 No PMT-SBA
• All PMT data with SBA-Borosilicate version of PMTs. All data without Aerogel
• Signal events of Bs ff for PID studies
• About 20 K events used for each option
Current-Optics RICH1- Spherical Mirror ROC=2710 mm
Rich1-Optics-Version3 RICH1-Spherical MirrorROC=3800 mm and optics tuning
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PID performance at Lumi2
This version of ‘new optics’ has better performancecompared to ‘current optics’.
Current-Optics
RICH1-Optics-Version3
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PID performance at Lumi20
Current-Optics
RICH1-Optics-Version3
This new optics has better performance.
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PID comparisons
Performance loss due to Lumi2 Lumi20 is mostly recovered by improved optics. (ie. ‘Red ’ marginally below the ‘black ’ ).
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dll_K > 0.0dll_K >4.0
Lumi20-S, Current Optics
dll_K >0.0dll_K > 4.0
Lumi2-S, Current optics
MeV MeV
MeV MeV
K K efficiency p misID probability
PID vs. Momentum
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dll_K >0.0
PID vs. Momentum Lumi2-S, RICH1-Optics-Version3
dll_K > 4.0
dll_K >0.0 dll_K > 4.0
Lumi20-S, RICH1-Optics-Version3
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Epilogue
• The number of PMTS 1920 2688 in RICH1 2688= 12*7*2*16
Possibilities to reduce this: (a) Have a sparse distribution of PMTs near the outer edges of the acceptance. May be tried to to see the effect on PID (b) Limit the acceptance to a smaller value.
• Rotating RICH1 : Not done yet.
• Number of scintillation hits in RICH2 : to be improved.
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Summary
Improvements in the optics configuration resulted in improving the PID performance.
Possibilities exist for further improvements in PID performance and to reduce the number of PMTS used.
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BACKUP SLIDES
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PID vs Angle
In all plots dll_K > 4.0
9.3GeV<P < 30 GeV
Lumi20-Smrad
9.3GeV<P < 30 GeV
Lumi2-S
mrad
K K efficiency p misID probability
9.3GeV<P < 30 GeV
Current Optics RICH1-Optics-Version3
mrad
mrad
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RICH1-Optics-Version3
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Resolutions from Brunel
RICH1-Optics-Version3
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P PT
Track polar angle
MeV MeV
mrad
Track Parameters
Tracks used in RICH PID algorithm
Lumi2-S
Current-Optics