The ATLAS Semiconductor Tracker SCT Assembly SCT Requirements

The ATLAS Semiconductor Tracker (SCT) Assembly SCT Requirements • pseudo-rapidity coverage: 2. 5 • small angle stereo in order to avoid ambiguities • each detector to provide resolution of 20 μm in r and 700 μm in z • two-hit resolution of the order of 200 μm • each detector at least 97% efficiency • all layers to operate for full lifetime of ATLAS SCT Assembly Oxford (Barrel) Silicon surface: ~62 m² -> 4088 modules -> ~6. 3 million readout channels Liverpool and NIKHEF (endcaps) * ~4000 cables & ~13000 fibers required to transfer information from these channels * Cooling System keeping electronics, modules and cables at low temperature Silicon module (endcap) * Hundreds of sensors providing information about the environmental parameters Final assembly site Interaction with other Subdetectors Hardware and Software Interlocks Warnings Alarms Errors Actions Handling DCS CERN – SR 1 building -> dedicated facility for Inner Detector assembly and integration Interaction with LHC Accelerator and External Systems Common Architecture for all the LHC experiments (Joint Controls Project – JCOP) Distributed Back-End (BE) System Front-End (FE) System üSupervisory Control and Data Acquisition System (SCADA) -> PVSS II üHierarchical organization simulates the natural mapping of the experiment üFinal State Machine (JCOP) States and transitions handling üEmbedded Local Monitor Board (ELMB) üStandard Analog&Digital I/O Radiation hard – Low power consumption DCS parameters Reading out the SCT components ** Power provided by the High Voltage (HV) and Low Voltage (LV) power supplies. - Each LV card controls 4 electrically independent LV channels, outputs logical signals for the FE electronics of the modules (RESET and clock SELECT) and 4 different voltages: the analog (Vcc) and digital (Vdd) voltages for the readout chips as well as VCSEL and PIN bias voltages for the optical communication of the module. Two thermistors mounted on each barrel module and one thermistor mounted on each endcap module are read out through the LV cards. -Each HV card controls 8 electrically independent HV channels, providing bias voltage to the detector modules. Temperatures and Currents Barrel 3 acceptance tests Barrel 3 Noise Xtalk effect in the chips of the module give higher contribution than the temperature difference between the two sides of the module (bottom side hotter than top side) Hybrid temperature measured – cooling pipe temperature along the barrel Cooling Pipe temperatures ** Monitoring of environmental parameters: 1. the temperature close to the outlets of the cooling pipes; 2. the temperature near the edge of the barrels, to give information about possible deformations in the shape of the support structures; 3. the air temperature inside the detector; and 4. the humidity inside the detector. Anna Sfyrla European School of HEP – 2005 University of Geneva