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Using the EUDET pixel telescope for resolution studies on silicon strip sensors with fine pitch. Thomas Bergauer for the SiLC R&D collaboration 21. May 2008. Aim of the effort. The goal of this testbeam:
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Using the EUDET pixel telescope for resolution studies on silicon strip sensors with fine pitch Thomas Bergauer for the SiLC R&D collaboration 21. May 2008
Aim of the effort The goal of this testbeam: • Evaluate the best strip geometry of silicon strip sensors with 50 micron pitch to achieve the highest possible spatial resolution • For this purpose we are using a dedicated mini sensor with different zones, each with a different strip geometry: • Different strip widths • 0, 1 or 2 intermediate strips • We are using the fine resolution of the EUDET pixel telescope to get high precision tracks to determine the residuals for our DUTs [Devices under Test]
DUT Sensors Last sensor order at HPK from SiLC collaboration contains a multi-geometry mini sensor: 256 strips with 50um pitch 16 zones with 16 strips each Layout constant within each zone Strip width and number of intermediate strips vary between the zones TESTAC: 3
DUT Sensors • DUT sensors have been intensively tested in Vienna, e.g.: • IV curves on all sensors • CV curves to determine full depletion voltages • approx. 60V • Measurement of the interstrip capacitance reveal different values for each zone: • Capacitance scales linearly with strip width • Different offset for region with one or two intermediate strips
DUT Module 9 modules have been built in Vienna: Front side: Back side:
Arrangement on Telescope DUTs • Stack of 8 DUT modules are mounted onto XYZ-stage of telescope by the help of a small adapter table: • Since motorized stage allows also rotations of the DUT we will rotate one of the modules within the beam DUTs
DAQ for the APV25 chip • Frontend (FE) Hybrids are connected to Repeater Boards (REBO) • HV is coming from Keithley Source-meter via small board directly to FE (not shown) • Two 9U VME Boards with FADCs are reading data and digitalize them • NECO Board is the controller and distributes clock and trigger (via SVD3_Buffer board) • PC running CVI (LabWindows) is used for online monitoring and to store data NECO board has LVDS I/O to directly read trigger and timestamp data from TLU box (Thanks to David Cussins for providing a TLU box for testing this feature already weeks ago)
DAQ Hardware and Software • DAQ Hard- and Software (including predecessors) has already been used for more than 10 testbeams in the past. • Thus, everything is pretty stable.
Timing • Trigger is distributed from TLU box to telescope and our setup • Clock (40MHz) is generated locally by NECO • Latency can be adjusted by both NECO and APV chips • APV25 chip has 50ns shaping time and analog pipeline of 192 cells (corresponds to approx. 4us maximum delay) • Additional delays introduced by cables • DAQ online monitoring allows easy live adjustment of timing
Data Analysis Offline data analysis of DUT data: • Pedestal subtraction • Common mode correction • Hit finding, Clustering • Peak time reconstruction • Track Reconstruction (non existing) We have three possibilities for tracking: • Use EUDET software as proposed by Ingrid • Need to transfer our data into LCIO format • Use SiLC (Prague group) analysis software written in ROOT • Transfer data from telescope and DUT to ROOT files • Include tracking algorithms in Vienna Analysis code • Transfer data from telescope into proprietary ROOT files } Existing Vienna analysis software
Summary • We will test the spatialresolution of a mini sensor with different geometric zones using the EUDET telescope as reference • The testbeam starts next week (May 30th) • We feel well prepared for Data Taking • Everything is ready and source tests on the modules have been performed on the lab test bench in Vienna (successfully) • TLU integration has already been successfully tested • Setup will be transferred to CERN beginning of next week • Offline Analysis: Vienna analysis code works up to cluster finding and zero suppression • Different options for Track Reconstruction • We have a diploma student in Vienna who will perform this analysis