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SSD beamtest analysis St éphane Plumeri Institut de Recherches Subatomiques (IReS), Strasbourg. ITS week 20 – 23 October 2003. ALICE collaboration. Outlook. StripTracking software Noise, pedestal and common mode shift Signal and signal to noise ratio Cluster shape Charge matching
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SSD beamtest analysisStéphane Plumeri Institut de Recherches Subatomiques (IReS), Strasbourg ITS week 20 – 23 October 2003 ALICE collaboration
Outlook • StripTracking software • Noise, pedestal and common mode shift • Signal and signal to noise ratio • Cluster shape • Charge matching • Conclusion S.Plumeri (IReS) - ITS week
StripTracking software Authored by Dirk Meier at CERN (1997) and modified by J. Baudot, C. Suire and S.Plumeri (IReS) for STAR and ALICE SSD beamtests. StripTracking is a C++ program linked with root libraries StripTracking can: • Measure noise and pedestal • Find hits • Correlate hits on each side S.Plumeri (IReS) - ITS week
Noise ITC’s modules: Module 3: 357 e- P side 573 e- N side Module 4: 365 e- P side 573 e- N side Canberra’s modules: Module 1: 440 e- P side 1458 e- N side Module 2: 415 e- P side 1369 e- N side For each module V = 45V S.Plumeri (IReS) - ITS week
Pedestal Pedestal = mean value of charge over the run 2100 – 2200 ADC counts for all modules Nearly the same for N and P side S.Plumeri (IReS) - ITS week
Common mode shift Standard deviation of cms distribution over events, with : Seems to increase with distance from power supply S.Plumeri (IReS) - ITS week
Signal Charge in clusters (threshold: seed strip S/N>5 neighboors S/N>3 ) S.Plumeri (IReS) - ITS week
Signal Charge in clusters (Correlation between two sides and geometrical cut) S.Plumeri (IReS) - ITS week
Signal to noise ratio Problem on canberra’s module N side S.Plumeri (IReS) - ITS week
Cluster shape Bad results on canberra’s N side S.Plumeri (IReS) - ITS week
Charge matching Default on ITC’s module: maybe due to noisy strips ? S.Plumeri (IReS) - ITS week
Conclusion Good modules performances But: • Origin of high cms? • Too much noise on N side of canberra’s module Next step: Tracking S.Plumeri (IReS) - ITS week