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Outer Tracker Test beam preliminary results. Outer Tracker Status Report. J. Nardulli , G. van Apeldoorn, S. Bachmann, . Bauer, E. Bos, Y. Guz, T. Haas, T. Ketel, J. Knop, M. Nedos, A. Pellegrino, T. Sluijk, N. Tuning, U. Uwer, P. Vankov, D. Wiedner, A. Zwart. Introduction. Outline:
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Outer Tracker Test beam preliminary results Outer Tracker Status Report J. Nardulli, G. van Apeldoorn, S. Bachmann, . Bauer, E. Bos, Y. Guz, T. Haas, T. Ketel, J. Knop, M. Nedos, A. Pellegrino, T. Sluijk, N. Tuning, U. Uwer, P. Vankov, D. Wiedner, A. Zwart.
Introduction • Outline: • Setup • Trigger and Data Acquisition • Silicon Telescope • Multiple Scattering Calculation • Outer Tracker Analysis and preliminary results • Outlook
Setup (II) • Legenda • S1,S2,S3 are scintillators. Dimensions (8mm*8mm) • P1,P2,P3 are X/Y Silicon planes (4cm*4cm). Each plane reads out 1280 channels. 640 in X and 640 in Y. • M0,M1,M2,M3 are 4 OT modules produced in Warsaw (340mm*2500mm). • S4,S5 are Scintillators. Dimensions ~(20cm*10cm).
Trigger and Data Acquisition • 2 Independent Read outs: • OT • Silicon • 2 different run schemes • OT stand alone (see Mirco) • OT + Si Telescope
Trigger and Data Acquisition OT + Si Telescope • Main characteristics : • Rate : 10Hz • Trigger : Coincidence of the 5 Scintillators • Size of Si illuminated 2 straws illuminated per layer • Scintillators give time reference
Telescope resolution The residual of the Si clusters is ~ 12 micron Accuracy of prediction limited by Multiple Scattering. X Residual Plane P3 Resolution = 12µ Si Planes
Multiple Scattering Calculations General Formula: X_0 = Radiation Length x = Thickness p = Momentum q = Charge d = distance c = velocity We get: Third Si_plane (d = 389mm): 57.02 micron Third Scintillator (d = 400mm): 72.45 micron Common contribution: 96.71 micron Values cp = 6000 MeV Scintillator) x= 4mm; X_0(Scint) = 42.4cm Si_Plane) x= 0.6mm; X_0(Si) = 9.37cm
Tracks Selection • Strong selection on good tracks: • -0.0005 < Horizontal slope < 0.0005 • -0.001 < Vertical slope < 0.001 Preliminary Vertical Track Slope Horizontal Track Slope
OT Analysis • OT Parameters: • 4 Short modules Ar/Co2 : 70/30 • HV Scan [1475 : 1725] V • Threshold of FE [500 : 900 ] mV • Parameters varied for 2nd and 3rd module • Preliminary. Only looking at 2 straws: Mod 1, Ch 104, Layer B • Mod 2, Ch 23, Layer A Main Points: -Drift Time distribution - Cross Talk - Time – distance relation (R(t)) - Resolution - Efficiency
Drift time Distribution Mod 1 Ch 104 HV = 1550 V Mod 2 Ch 23 HV = 1550 V Drift time (0.4*ns) Drift time (0.4*ns)
Cross TalkPreliminary Estimation Mod 2 Ch 23 ; HV = 1550 V Mod 2 Ch 23 ; HV = 1725 V Estimated CrossTalk = 4.1 % Estimated CrossTalk = 32.9 % Higher Voltage Larger signal Larger Crosstalk in FE
R-t CalibrationFirst rough estimation First Rough R-T Calibration: necessary for the Resolution. 1 straw = 4.9mm Plot is fitted with a second order polynomial The values found are used for the Resolution calculation. Drift time (0.4*ns) Module 1 – Ch 104 (HV =1550V) Predicted x position (µm)
Resolution • Rough R-T Calibration • We are looking at ½ straw: 2.5mm • Remember the Mul.Scat. Calculation ~ 96.71 micron • This is a monitoring value and not the final result !!! Module 1 – Ch 104 (HV =1550V) Resolution 315 micron
Multiple Scattering Measurements • Procedure • Resolution measured for various Energies • With and without S3 Multiple scattering is obtained via:
EfficiencyPreliminary Estimation All the events, Ch 103 and 105 not hit All the events Ch 104 has a hit. Ch 103 and 105 not hit Efficiency Module 1 – Ch 104 (HV =1550V) Efficiency = 94 % 1 straw = 4.9mm Predicted x position
Efficiency and ResolutionVarious HV values Efficiency 100 90 Preliminary 1550 HV (Volt) Resolution Threshold value : 700 mV 360 300 1550 HV (Volt)
Efficiency and ResolutionVarious Threshold values Efficiency 100 90 Preliminary 700 Threshold (mVolt) Resolution 350 250 HV value = 1550 V 700 Threshold (mVolt)
Outlook • First results look promising, but still much to do… • Redo the RT Calibration • Look at all the 16 straws • Investigate and optimize the angle cuts • Get final numbers for Resolution, Efficiency • Determine Cross Talk
Conclusions The test beam was a lot of work… but a lot of fun too !!! Who pushed the emergency at 3:00 am?