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CMS ECAL Status, Test Beams, Monitoring and Integration. Outline. ECAL Integration Status Monitoring Project. CMS ECAL Lead-Tungstate Crystal Calorimeter. 0.45 m. ~6.35 m. 90 t of PbW0 4 ~76000 Channels
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Outline • ECAL Integration Status • Monitoring Project A.Bornheim - DOE Review 2007 - CALTECH
CMS ECALLead-Tungstate Crystal Calorimeter 0.45 m ~6.35 m • 90 t of PbW04 • ~76000 Channels • Barrel segmented in 36 SuperModules (SM), each endcap in 2 Dee’s, endcap equipped with a Preshower detector. • Design resolution 0.5% above 100 GeV. • Dynamic range 0.04 GeV to >1000 GeV. • Very powerful detector for all lepton and photon base physics. • Crucial for H 2.6 m A.Bornheim - DOE Review 2007 - CALTECH
Electronics Integration Y. Yang ECAL Integration Center • All 36 SMs have been equipped with electronics and pre-calibrated with cosmic rays. • Very tight quality control. Spotted per-mille level problems which were fixed. • Tight schedule was kept with substantial help from the entire ECAL collaboration. Caltech students worked shifts for 4 months. A.Bornheim - DOE Review 2007 - CALTECH
ECAL Insertion at LHC Point 5 ECAL Insertion P5 T. Orimoto V. Timciuc • One half of barrel ECAL (EB-) has been inserted into CMS in June. The second half is being inserted now (1 SM every 2 days). Expect to finish by the end of the week. • More than 99.9% of all channels are functioning perfectly. • Barrel ECAL will be cabled in September, to be fully integrated in global data taking soon after. A.Bornheim - DOE Review 2007 - CALTECH
CMS ECAL Endcap J. Veverka ECAL Endcap Monitoring Fibers • Endcap assembly now in high gear. Dee’s are equipped with crystals, electronics, monitoring etc. • One third of all endcap crystals are at CERN; confident that all crystals will be delivered in time. • Goal is to insert both endcaps for physics running in 2008. Extensive test beam in 2007. A.Bornheim - DOE Review 2007 - CALTECH
ECAL Preshower Preshower EE Y. Ma • The Preshower assembly (part of the ECAL endcap) is now also getting on an accelerated schedule. • Testbeam 2007 with preshower, ECAL endcap and HCAL and possibly with endcap only for precision tests. • Caltech group is studying the preshower utilization. It is an integral part of ECAL which has yet to be brought to the same level of integration and understanding as the barrel ECAL. A.Bornheim - DOE Review 2007 - CALTECH
CMS ECAL Timeline • Insertion of last SMs is ongoing now. • Cabling of barrel ECAL done by September 2007. • Participation in CMS global runs starting October 2007. • Assembly and integration of Endcaps between now and March 2008. • Insertion of Endcaps shortly before closure of detector in 2008. • Preshower on a very similar time scale. • Start commissioning with physics data with the first collisions in 2008 • Reach design performance in 2009. A.Bornheim - DOE Review 2007 - CALTECH
ECAL Performance in the Test Beam ≤1% effect due to crystals “staircase” geometry predicted by simulation is measured in data with 1‰ accuracy Comparison of inter-calibration coefficients obtained with the beam (Cbeam) and with cosmic rays (Ccosm) • All Supermodules have been pre-calibrated with cosmic rays with an average accuracy of 1.5% • Testbeam measurements and MC simulation agree at the level of 0.1% A.Bornheim - DOE Review 2007 - CALTECH
Laser Monitoring Performance in Test Beam Restoring design resolution after irradiation Monitoring stability better than 0.1% • Monitoring system has been operated at design specification during test beam 2006 for more than 1000 hours. • Transparency corrections have been studied and tested. • Caltech students have served several 100 hours of shifts in the test beam campaign 2006. C. Rogan A.Bornheim - DOE Review 2007 - CALTECH
ECAL Laser Monitoring Test Beam Data Damage Recovery Recovery Damage • ECAL Crystals are radiation hard, but do change transparency under irradiation by several percent. • Measure transparency change every 20 minutes with a precision of better than 0.1 %. • Correct all physics data to ensure that the inter-calibration of all ECAL channels is not affected. APD VPT A.Bornheim - DOE Review 2007 - CALTECH
Laser Monitoring Project • In 2006 we processed all test beam data in quasi-online mode at CERN. Precision stability better 0.3% available within 15 minutes after data taking, better than 0.1% offline. • Since 2007 we are responsible for the entire ECAL monitoring project (jointly with Saclay) with Bornheim as the task leader. • Three students (Timciuc, Ma, Veverka) and Orimoto work on the monitoring project at CERN to fulfill their service requirements. • The project is now a task within the newly formed ECAL DPG group. A.Bornheim - DOE Review 2007 - CALTECH
Laser Monitoring Workflow DAQ GT Disk Buffer Laser Farm FilterFarm/HLT LASER Gap Events Saclay CALTECHSaclay Raw APD/PN Y. Ma CMS Online DB Repackage Laser Data Online P5 Corrected APD/PN J. Veverka Offline Tier0 CAF Offline Reconstruction Offline DB T. Orimoto V. Timciuc A.Bornheim - DOE Review 2007 - CALTECH
Integration of Laser Source at P5 CMS Laser Amplitude ECAL Global Trigger Time [s] LaserSystem TTCci EMTC Online Laser Data Processing Farm Gap Events • Monitoring has to happen continuously during normal data taking. • Laser system and laser DAQ synchronized with LHC clock and CMS DAQ. • Monitoring data will be read during special calibration trigger and funneled into a dedicated stream. • Online processing of data to achieve fast feedback. • All hardware is commissioned and ready to go at P5. Real Time Laser Trigger Sequence A.Bornheim - DOE Review 2007 - CALTECH
Laser Monitoring: Online Data Flow Disk Buffer Laser Farm FilterFarm/HLT Gap Events Yousi Ma DAQ GT LASER CMS • Laser monitoring data will be acquired during LHC “gap” events. Gap events will arrive at the Filter Farm, containing, among other data, the ECAL laser event data. • One transparency measurement is based on a few hundred laser events on one light monitoring module. The ECAL laser data has to be extracted from the gap events and funneled into the CMSSW job running on the Laser Farm. • In particular, the data must be sorted into files containing all the laser events for one transparency measurement. This is being implemented in a standalone application by Y. Ma. Online DB P5 Offline Tier0 CAF Offline Reconstruction Offline DB A.Bornheim - DOE Review 2007 - CALTECH
Laser Monitoring: Databases & Corrections • Once the laser data is sorted and processed to extract APD/PN values, this data must be inserted into the OMDS (the “online database”) located at Point 5. • The data must then be transferred using the online-to-offline (O2O) copy procedure, during which raw APD/PN ratios have to be normalized and corrected (eg. for the pulse width non-linearity). • The laser APD/PN ratios, reference values, and scale factors necessary to implement the transparency correction will be stored in the ORCON/ORCOFF “offline database” • V. Timciuc is currently developing software in the CMSSW framework for storing and transferring the data between databases, and J. Veverka will be joining him to work on the corrections Vladlen Timciuc Jan Veverka DAQ GT Laser Farm Disk Buffer FilterFarm/HLT LASER Gap Events CMS OMDS P5 O2O Offline Tier0 CAF Offline Reconstruction ORCON ORCOFF A.Bornheim - DOE Review 2007 - CALTECH
Laser Monitoring: Transparency Correction Toyoko Orimoto • The physics data has to be corrected for the effects of the crystal transparency change, and this will be done in the offline reconstruction. • For the correction, we will use the APD/PN ratios, reference values, and correction scale factors stored in the offline ORCOFF database. • The data will be interpolated in time in order to apply an accurate correction to physics events. The correction must be recalculated each time the interval of validity is updated. • We must develop a strategy to validate the laser transparency correction in-situ. • Currently working towards implementing the correction for CSA07. DAQ GT Disk Buffer FilterFarm/HLT LASER Gap Events CMS P5 Offline Tier0 CAF Offline Reconstruction ORCOFF A.Bornheim - DOE Review 2007 - CALTECH
Monitoring Time Line to Physics Running • Participate in CSA07 with first offline transparency correction. • Participate in in CMS global runs with monitoring system starting in September 2007. • Implement and commission full monitoring scheme by early 2008. • Start routine running as soon as detector closed in 2008. • Start analysing data and tune performance as soon as beams circulate in LHC. Expected initial monitoring stability : ~0.3 % • Reach design performance for the monitoring 2008. Expected monitoring stability <0.1%. • Exercise synergies between monitoring effort and inter-calibration effort to maximize physics output of ECAL. A.Bornheim - DOE Review 2007 - CALTECH
Summary • CALTECH is now in charge of the entire monitoring project. • ECAL integration is progressing smoothly. Expect to have a full ECAL available for physics data in 2008. • Extend our leadership further to ensure ECAL reaches design performance. A.Bornheim - DOE Review 2007 - CALTECH