Calorimeter Calibration

1. Calorimeter Calibration • Electronics Calibration • Online Calibration Software • Database handling • Offline Calibration Slides contributed from: U. Bassler, M. Bhattacharjee, L. Groer, F. Machefert, S. Muanza

2. Electronics Calibration Calorimeter Electronics Trig. sum Bank 0 Calibration SCA (48 deep) SCA (48 deep) x1 Filter/ Shaper Output Buffer Preamp/ Driver SCA BLS x8 Calorimeter SCA (48 deep) SCA (48 deep) Bank 1 Goals: • Calibrate electronics to better than 1%: • 1. Measure Pedestals due to electronics & Ur noise • 2. Determine 0 suppression limits • 3. Study channel to channel response variation • 4. Study linearity • Calorimeter electronics commissioning: • 1. bad channels • 2. trigger verification • 3. mapping

3. 6 commands (3x2) 96 currents PIB Trigger Pulser Preamps box Power supply 2 Fanout (2x3x16 switchs) switch Calibration System (LAL Orsay, LPNHE Paris) • 12 units for calorimeter + 1 for ICD •  smallest unit to be calibrated: 1 ADC crate

4. Calibration System: Pulser + Fanout • Pulser: • current generator • command trigger • pulse shape controller Active FanOut: “pulse formation” : receiving a command signal, switch is opened  Hardware installation nearly completed

5. Calibration System: Pulser Interface Board • interface epics/pulser • produces event header • automated calibration procedure

6. RAM L3 GUI Pulser 1 - Pulser 13 Pulser 1 - Pulser 13 Request Status CPU ECL/TTL Counter Serial Port Trigger Pulser Pulser Interface Board • Automated calibration • procedure: • Minimize number of • downloads from host to • front-end • Loops on signal height, • delays (initial and last • value, number of steps) • Count number of triggers

7. Software: Pulser Communication GUI for pulser setting TAKER COOR data block structure COMICS EPICS Hardware database VME address of RAM registers VBD PIB program and protocol structure L3 event header PULSER

8. Software: GUI for Pulser Control • Pulsers Configuration to download: • signal height (DAC) • Enable for each pulser channel (patterns) • Commands • Delay • Calibration loop parameters: • linearity/timing • number of events per step • step size • pulser patterns

9. Calibration Data Flow • CALIBRATION PROCEDURES: 2/3 times a week • pedestal runs: ped,  • pulser runs: gain1, gain8 after validation • ONLINE DATABASE: • constants ordered • by crate#, card#, channel # • OFFLINE DATABASE: • optimized format for reco possible copy • L3: • “golden sample” • BLS: • integers for 0-suppression • constants updated • RECONSTRUCTION: • 0-suppression parameters • channel and gain inter-calibration • constants updated • TRIGGER: • no calibration

10. Software for DAQ Commissioning • grabs data from distributor • calculates , /channel • reports running , /channel • prints status report • being used to debug CAL crates 10 & 11 Version of Calibrationcal_elecruns on online HOST (since Feb, 2000 part of commissioning milestone) Run type: pedestal Sigma tails from preamp capacitance

11. Software for DAQ Commissioning Run type: pulser Mean vs. channel Sigma vs. channel • Integrate with L3 (end of July) • Communication between L3 and Host (July) 

12. Calibration in the Reconstruction raw data chunk: packed format ADC hits, crate #, card #, tower #, layers# • OFFLINE DATABASE: • crate #, card #, tower #, layers# • ped, , 0-suppr., gain1, gain8 cal_unpack_package FE data chunk: unpacked format ADC hits, crate #, card #, tower #, layers# cal_calib_package calibration manager: access to database for all subdetectors Calibrated data chunk: keeps ordering energies, crate #, card #, tower #, layers# cal_calibrator: fills calorimeter calibration classes cal_geom_package Reconstructed data chunk: physics units energies, , 

13. Software for database handling: • final online database definition, design & implementation • on going (June – July) – Database meeting (August)? • creation of database server • procedure to read/write data into online database • online software group • definition of offline database table and calibration classes • creation of offline database tables and database server • sql to transfer data between online/offline database • creation of offline calibrator classes and code

14. Offline Calibration • Intercalibration: • Phi Symmetry • No beam polarization => symmetry in j • Run I: symetrize energy flow in j • Could use sample • (1.6 M expected in Run IIa) • verify the sampling fractions: • Method: for a given EM layer at a given eta adjust the cell <E>cell to the <E> of all cells in phi

15. EM Energy Scale • Resonances: • Using sets the absolute energy scale • Check the results with other known resonances: • Method: • Fitting the Z peak determines and • Use other resonances to correct for non-linearity at low pT • E/p: select isolated, low energetic electrons and compare cluster energy with track momentum

16. Jet Energy Scale Compare two processes usable for JES calibration: vs • Aim: • complement at high Et • MC independent cross-check • Advantages: • very low background • harder Et spectrum • Drawbacks: • lower statistics

17. Calibration Working Week • 25-29 Sept. @ Paris:Confirmed attendants: Lyon (4), Paris (1), Orsay (2), Marseille (2), + Mainz (2),+ B. Hirosky, J. Hobbs, +Anybody Interested • Prepare calibration with physics events: • Inventory of Run I knowledge • Infrastructure for Run II Offline Calibration (CAFIX++ ?) • Strategies for phi intercalibration and EM scale • Triggers and MC for resonances, • Peak reconstruction and fitting procedures • E/p matching • Develop common software • Start the Jet Energy Scale program