The Muon Spectrometer Commissioning and Upgrades Joao Guimaraes da Costa for the ATLAS Harvard Group DOE Site Visit

8/21/2009LPPC Harvard ATLAS Group2 Harvard People Working in the Muon System Faculty: –George Brandenburg (retired) –Melissa Franklin –Joao Guimaraes da Costa –John Huth –Masahiro Morii Postdocs: –Alberto Belloni –Kevin Black –Shulamit Moed Technical support –Electronics shop Sarah Harder (retired) John Oliver, Meghan Kundoor –Mechanical shop Steve Sansone (List incomplete as several people involved in the construction have left) Graduate students: –Laura Jeanty –Michael Kagan –Lashkar Kashif –Verena Martinez Outschoorn –Srivas Prasad –Emily Thompson (Univ. of Mass, Amherst) –Giovanni Zevi della Porta Undergraduate students –Michael Fountaine –Jack Kearney –Tomo Lazovich –Curt Nehrkorn (Dark Red: People working at CERN)

8/21/ The ATLAS Muon System Barrel (MDT+RPC) Small Wheel (MDT+CSC+TGC) (MDT+CSC+TGC) Big Wheel (MDT + TGC) Big Wheel (MDT + TGC) Outer Wheel - EO (MDT) (MDT) Chamber construction: BW+ SW (80) Integration: BW+SW+EO+BEE+EE Electronics and DAQ: Full MDT Commissioning Analysis: Full MDT Chamber construction: BW+ SW (80) Integration: BW+SW+EO+BEE+EE Electronics and DAQ: Full MDT Commissioning Analysis: Full MDT “EE”“EE” Endcap (BW+SW+EO+EE) BEEBEE (MDT: 2 x 96)(2 x 80) (2 x 31) (2 x 16) (2 x 40) (580)

8/21/2009LPPC Harvard ATLAS Group4 Monitored Drift Tube (MDT) Chambers Ar/C0 2 3 bar Gain: 2 x 10 4 ; HV= 3080V Max drift time = ~ 700 ns Single tube resolution: ~ 80 μm Al tube t0

8/21/2009LPPC Harvard ATLAS Group5 5 On-Chamber Readout Board ASD/TDC Mezzanine board designed, produced and tested at Harvard (collaboration with BU) –George Brandenburg, John Huth, Sarah Harder, Joao Guimaraes, John Oliver, Werner Riegler 18k Mezz boards (full MDT system) 67k ASD chips ASD/TDC Mezzanine board designed, produced and tested at Harvard (collaboration with BU) –George Brandenburg, John Huth, Sarah Harder, Joao Guimaraes, John Oliver, Werner Riegler 18k Mezz boards (full MDT system) 67k ASD chips Tests/repairs LPPC electronics shop Sarah Harder Giovanni Zevi della Porta Tests/repairs LPPC electronics shop Sarah Harder Giovanni Zevi della Porta

8/21/2009LPPC Harvard ATLAS Group6 Integration, Commissioning and Data Preparation Installation Integration Performance Electronics (Mezz, CSM) Power supplies Readout Drivers (MRODs) DAQ Online Monitoring Control Room Operations Control Room Operations Offline Reconstructio n Magnetic Field Studies Coordination of Software Releases Offline Monitoring Firmware upgrades Cosmic Ray Analysis Mostly in prior years Alignment studies Alberto Melissa Cosmic Ray Runs Oct Muon Slice Jun Aug. 2009

8/21/2009LPPC Harvard ATLAS Group7 Major Installation and Maintenance Operations this Year  Maintenance of BWs –Installation of radiation hard optical readout fibers Side C: November 2008 Side A: May 2009 –Fixed minor gas and electrical problems in a few chambers  Maintenance of SWs –Fixed minor electrical and gas problems  Integration of all BEE chambers –Integration in February 2009  Installation of EE chambers –Integration in DAQ on-going  Replaced readout boards in all barrel MDT CSMs –Operation at 50 MHz Collaboration with UM, BU, Barrel Colleagues and Technical Division Integration

8/21/2009LPPC Harvard ATLAS Group8 Status of the MDT Chambers Very low percentage of failed components –Readout channels: ~0.4% 2.5% before shutdown 1098 chambers will be operative by start of collision data –Including 8 EE chambers being integrated now –Missing 52 EE chambers

8/21/2009LPPC Harvard ATLAS Group9 DAQ activity Harvard group is playing a major role in Muon DAQ operations –Alberto Belloni is the Deputy Muon DAQ Coordinator Only MDT DAQ expert resident at CERN –Integrated all endcap chambers Including MROD optical fiber installation –Responsible for Run Control configuration –Organized and led commissioning of chambers Prepare and take test runs –For instance, noise runs BEE, EO Check readout/HV mappings Track chamber problems Identify and assign repair activities –Close contact with Detector Control System (DCS) support group Experience in detector installation and commissioning Support of power system –Students Laura and Giovanni and new postdoc joining this year Run Control MROD

8/21/2009LPPC Harvard ATLAS Group10 More DAQ contributions Improvements of DAQ system –Provided numerous scripts for most common expert tasks –Developed the MDT Control Panel Graphical interface for chamber RO configuration Giovanni and Tomo –Stopless recovery for MDT chambers –High rate operation at 75kHz –Reduction of transition times during start/end of run

8/21/2009LPPC Harvard ATLAS Group11 Operations in the Control Room Constant presence in the control room since Feb. 2007Constant presence in the control room since Feb –DAQ Expert –DAQ Expert: Alberto Belloni ( on-call expert ), Verena Martinez, Srivas Prasad –Monitoring Expert –Monitoring Expert: Shulamit Moed, Michael Kagan –MDT Endcap Coordination –MDT Endcap Coordination: Joao Guimaraes –Shifters : Muon DAQ: Verena, Srivas, Giovanni, Kevin, Lashkar, Laura, Michael Muon Data Quality Assessment: Michael Kagan Run Control: Verena Martinez Shift Leader: Joao Guimaraes, Alberto Belloni Defining procedures, improving documentation –Many contributions in DAQ Manuals for shift crew Twiki pages for shift crew Training MDT shifters during monthly training sessions (Alberto) –Muon online monitoring (DQMF) Manuals for shift crew –Event display configuration Atlas Control Room

8/21/2009LPPC Harvard ATLAS Group12 Pulser runs New testing and calibration tool Calibration capacitor on mezzanine boards –Controlled test of each readout channel Framework for automatic startup of MDT pulser runs and analysis of results in preparation –Initial tests very successful Pulses in half of the tubes Cross-check of mapping In single tube, same pulse at same time (TDC)

8/21/2009LPPC Harvard ATLAS Group13 Magnetic Field Studies Understanding of magnetic field is one of the major challenges for muon reconstruction with real data –Magnetic field is highly inhomogeneous, specially in the transition region between the barrel and endcap –Correlation between simulations from currents in the coils and magnetic field reconstruction from ~1730 Hall probes Morii (together with Nehrkorn and Fountain) is continuing these studies More realistic model of the coils Inter-coil connections contribute with ~40-50 gauss at sensor positions Being added to field simulation

8/21/2009LPPC Harvard ATLAS Group14 Reconstruction Software Harvard group has made significant contributions to the muon reconstruction software for several years –Muon Track Reconstruction Development (MOORE) –New Segment Fitting Code for Cosmics (see later slides) Focus on validation and commissioning this year Muon Spectrometer/Combined Muon Performance Release Coordinator – Kevin Black –Tag collection, bug hunting, testing, defining muon software for each official release Muon Commissioning Software Manager – Kevin Black –Commissioning software configuration, prepare tags with developers, muon contact for Tier0 processing US ATLAS Muon Analysis Forum Convener/ US ATLAS Muon Software Contact - Kevin Black

Improvements and bug fixes 8/21/2009LPPC Harvard ATLAS Group15 Offline community very active Last month: 1205 new bugs in ATLAS code; 525 already closed T0 people complain about large events Kevin investigates and finds algorithm causing problems Developer fixes problem and provides tag of fixed software Kevin tests tag Collects tags to be used in next cache (i.e. update) Code re-run at T0

8/21/2009LPPC Harvard ATLAS Group16 Muon Track Segment Reconstruction Reconstruction in cosmic ray data –Problems: Tracks do not point to IP Cosmic rays not synchronized with LHC clock Time of flight between chambers not constant Developed new segment finding algorithm with floating t0 Code adopted by standard reconstruction Responsible for the Muon Track Segment common code – Srivas Prasad Muon arrival time (t0) not well defined AfterBefore Partially corrects poor calibrations Can be used in collision data until calibrations are satisfactory Good benchmark for software (in real data)

8/21/2009LPPC Harvard ATLAS Group17 Muon Track Segment Reconstruction Internal note: A. Belloni, K. Black, J. Guimaraes da Costa, V. Martinez Outschoorn, S. Prasad, In-situ t0 calibration for MDT segments, ATL-COM-MUON , CERN, 2009.

8/21/2009LPPC Harvard ATLAS Group18 Resolution studies Resolution not optimal due to several calibration issues: –Studied with toy MC and real data rt-relations and conditions Internal note: A. Belloni, K. Black, G. Brandenburg, J. Guimaraes da Costa, V. Martinez Outschoorn, S. Prasad, Muon Segment Studies: Calibration and Resolution, ATL-COM-MUON , CERN, Average: 60 μm per week 10 μm per 12 hours Old rt-relationsCrossing of multiple mezzanine cards Effect: μm (depending on how many mezz cards are crossed) Temperature effects Effect: 100 μm if not corrected (for 5 °C)

8/21/2009LPPC Harvard ATLAS Group19 Muon Detector Upgrades LHC upgrade plans: –Phase 1: L= 3x10 34 cm -2 s -1 in 2014 –Phase 2: L= cm -2 s -1 in 2018 (Super-LHC) Spectrometer designed for L= cm -2 s -1 (with x5 background rate scale factor) –Actual background level in the cavern is unknown –If SF=5 or larger, the innermost chambers in Muon Endcap will have degraded performance even in phase 1 US ATLAS Muon Upgrade Working Group: –Frank Taylor, Dan Levin, Jim Bensinger, John Butler, John Huth, Vinnie Polychronakos, Joao Guimaraes, Eric Hazen, Jay Chapman

8/21/2009LPPC Harvard ATLAS Group20 MDT Electronics Upgrades Very natural project for our group –LPPC electronics shop –Designed and produced current ASD chip and mezz cards Collaboration with BU, UM and Max Planck Institute –Letter of Intent submitted to CERN by MPI (in the process of joining) –Electronics suitable to standard MDT chambers and small-tube option being pursued by MPI Upgrades to the ASD chip (Harvard) –Reduce MDT deadtime, noise levels –Match the new smaller tubes with different shaping times –Short term goals: detailed study of signal processing chain at Phase 1 rates to determine how or if one should proceed with a new ASD Upgrades to the TDC (BU) and CSM (UM)  requires new mezz cards –Addresses bandwidth rate limitation MDT based track trigger  might require new ASD chip –Addresses the L1 trigger threshold sharpness

8/21/2009LPPC Harvard ATLAS Group21 Micromegas Technology Being considered for phase 1 to cover the region were the CSC was descoped (4 layers instead of 8) –If successful can be used in Phase 2 Combines trigger and tracking functions Technology being used by T2K and COMPASS Challenges: –Going to large areas ~1m x 2m with industrial processes (cost effective) –Need cost effective front-end electronics, including custom ASIC design US Collaboration: Arizona, Brookhaven, U. South Carolina, Brandeis, Harvard, MIT Spatial resolution ~ 100  m (  track < 45°) Good double track resolution Time resolution ~ 5 ns Efficiency > 98% Rate capability > 5 kHz/cm 2 Harvard is interested in the front-end electronics Initial stages of design started with BNL

8/21/2009LPPC Harvard ATLAS Group22 Micromegas upgrade at Harvard Small chamber being setup by Mercurio, Brandenburg with help from Steve Sansone

8/21/2009LPPC Harvard ATLAS Group23 Plan for Future Take good data efficiently! Muon spectrometer is ready for data-taking later this year –Endcap channel coverage is now over 99% Maintain DAQ responsibility for the MDT –Alberto Belloni (Deputy Muon DAQ Coordinator) –New postdoc Provide quick online/offline monitoring feedback –See Melissa’s talk Improve offline software tools –Kevin Black (Commissioning Software Coordinator/Muon Release Coordinator) Start muon spectrometer upgrade activities Use our knowledge of the muon system as a springboard for early physics analysis

8/21/2009LPPC Harvard ATLAS Group24 The End

8/21/2009LPPC Harvard ATLAS Group25 Magnetic Field Studies One barrel and two endcap air core toroids, with 8 superconducting coils BarrelEndcap Outer diameter20.1 m10.7 m Length25.3 m5.0 m # turns / coil Current20.5 kA Field in the bore0.2–2.5 T0.2–3.5 T Need precise (< 0.5%) field map over 20 x 20 x 25 m 3 Calculate the field from current in the coils Perturbations due to iron structures evaluated numerically Positions and shapes of the coils must be known to a few mm Surveys not reliable under operations conditions

8/21/2009LPPC Harvard ATLAS Group26 Magnetic Field Reconstruction dim. Hall probes are installed on the MDT chambers –Measure field to a precision of 5 gauss –Comparing the measurements with field simulation, one can fit the location of the coils Harvard (Morii) collaborates with Saclay and Dubna on field fit and reconstruction –Not enough measurements to constrain endcap coil positions –64 extra sensors added to endcap cryostat surface –May 2009: All probes commissioned and positions surveyed

8/21/2009LPPC Harvard ATLAS Group27 Current Magnetic Field Studies Characterization of magnetic field continues (Morii, Nehrkorn, Fountain) –Validation of FEM calculations of the field perturbations due to ferromagnetic materials in cavern –Detailed positioning of the ECT coils and the current leads geometry –Results: Inter-coil connections contribute with ~40-50 gauss at sensor positions (x10 sensor resolution) and will be added to the field simulation Connections between the 8 ECT coils Field 5 cm from loop

8/21/2009LPPC Harvard ATLAS Group28 Muon Track Segment Reconstruction Code adopted standard reconstruction –Ran on over 300 million cosmic events taken by ATLAS –Allowed for further validation of the software from cosmic data Uncovered other problems –Design hit resolution (~ 80 μm) achieved (fit of core distribution) Fitted t0 Barrel BO Endcap EM Internal note: A. Belloni, K. Black, J. Guimaraes da Costa, V. Martinez Outschoorn, S. Prasad, In-situ t0 calibration for MDT segments, ATL-COM-MUON , CERN, 2009.

8/21/2009LPPC Harvard ATLAS Group29 Muon chamber single counting rates at LHC design luminosity (Background SF = 1) Phase 1 rate (with SF=5): 1.5 kHz cm -2

8/21/2009LPPC Harvard ATLAS Group30 Further upgrades Bandwidth rate limitation –Upgrades to the TDC chip (BU) Exploring FPGA implementation –Need to understand radiation hardness and SEU –Upgrades to the CSM (UM) Upgrade to CERN GBT chip and new FPGA technology –These require new Mezzanine cards Possibility of a MDT based track trigger –Addresses L1 threshold resolution –Could be implemented within the Mezzanine and CSM cards FTK-type based trigger, allowing an ID-MDT match prior to L2 L1 implementation using coarse information from the MDT –Requires longer L1 latency –Likely to require a new ASD with two output streams: One going to the TDC, the other to a dedicated trigger processing unit to identify segments.