- Calorimeter Calibration Overview of the calorimeter electronics Online calibration: Online Calibration System Linearity measurements Systematic Effects Offline calibration:  -inter calibration Z reconstruction E/p in W-events Jet Energy Scale

Tevatron - Run II Upgrade Main Injector (new) Tevatron DØ CDF Chicago  Booster 1.96 1.8 s (TeV) 36x36 6x6 #bunches Run 2a Run 1b Main Injector and Recycler Increase of luminosity by reduced time between bunch crossing Increase of beam-energy Luminosity expected for 2002: 300 pb-1 DØ roll-in Run II start First Collisions Detector Commissioning; Timing in; Improve electronics, DAQ and offline p source Run 2b 140x103 1.96 typ L (cm-2s-1) 1.6x1030 8.6x1031 5.2x1032  Ldt (pb-1/week) 3.2 17.3 105 bunch xing (ns) 3500 396 132 interactions/xing 2.5 2.3 4.8

Run II Detector -detectors: MDT, PDT, scintillater – increased coverage Calorimeter: Fast Read-Out Electronics, Trigger Read-Out - preserve Run I performances in Run II environment Shielding Tracking Systems: solenoid, Silicon-vertex detector, Fiber-Tracker and PreShower detectors – provide momentum measurement -detector, calorimeter and SI-detector fully commissioned and operational Fiber Tracker/PS electronics to be completed and commissioned this spring

Calorimeter – Electronics Upgrade 55000 channels Ur/liq. Argon improvements for Run II: replacement of trigger and readout electronics to accommodate 132 ns interaction time 55k dual FET PreAmps 23k Switched Capacitor Arrays (SCA) with 8M storage cells 1200 Baseline Subtraction (BLS)-boards ~ 50 bad channels (~0.1%)

Calorimeter Electronics BLS: signal shaping, analog storage, baseline subtraction and gain selection Calibration BLS board 4 * L1 SCA (48 deep) Trig. sum x8 Filter/ Shaper x1 Preamp/ Driver BLS L2 SCA ADC x8 PreAmp Board Analog Storage LAr cell gain selection for further details see talk of Nirmalya Parua

Electronics Calibration Pulser Interface: configuration management 6 commands (3x2) 96 courrents PreAmp Box PIB Trigger PreAmp Card Pulse controller (Pulser) 6 Active Fan-outs with 16 switches: inductances form the pulse shape 12 Pulsers deliver: continuous current  pulse height command determines pulse start

Pulser & Fan-out switches

Pulser commissioning <slope>= 825 mAmps/DAC slopes A/DAC variation for all pulsers variation each pulser 1st pulser: used for ICD measurement of current/DAC for all pulsers <slope>= 825 mAmps/DAC all calorimeter pulsers within 0.2% variations of currents delivered within 1 pulser <0.1%

Pulse Shape Measurements measurement of all pulse shapes in situ with final installation (Pulsers, FanOuts and PreAmp Cards) study of systematic effects on signal amplitude, integral and timing correction factors for differences between pulses still to be derived

Linearity Studies Fit slopes a8 and a1 (or g = a8/a1) for all channels ADC  gain 8  gain 1 Response determine calibration coefficients for channel to channel variations verify pulser and electronics linearity compare response as function of pulse height for gain path 1 and 8 slope = a8 slope = a1 saturation DAC/1000 Fit slopes a8 and a1 (or g = a8/a1) for all channels ~0.25 ADC count/DAC unit (1 DAC unit  1 MeV) g  1 expected by design

Non-Linearity gain 1 gain 8 Residuals gain 1 gain 8 Comparison of residuals from a line (ax+b) after appropriate scaling for gain 1 and 8 below 10 ADC counts (<0.3%) above ~2 GeV non-linearity similar for all channels Intercept b non-zero: ~ 50 ADC counts ADC 10 DAC/1000 scaling residuals indicates non-linear behavior of SCA non-scaling residuals correspond to non-linearity of pulsers

Pulser offset Non-scaling observed for some pulsers at low DAC values for example: DAC/1000 ADC Residuals Non-scaling observed for some pulsers at low DAC values ADC Response non-scaling is due to pulsers with onset of current delivered at DAC>>0 effect corrected by applying appropriate shift DAC/1000

SCA non-linearity correction important at low energies functional form of SCA non-linearity correction function correction important at low energies 5 -5 ADC counts ADC counts/1000 ADC to energy conversion with universal function for SCA non-linearity 2 gains a8 and a1 ( or a8 and g = a8/a1 ) Residuals better than 5 ADC counts on the whole range for both gains

Effect of SCA-non linearity ~Energy/GeV 0.25 ADC count/MeV 4 0 10 20 30 40 50 GeV Gain 8 Gain  1 1 GeV 250 MeV for energies >200MeV non-linearity introduces an offset of ~250 MeV for the gain 8 measurements applied to Ze+e- events: peak at 89.6 GeV without any scale correction (MC 89.9 GeV) raw distribution after correction

Calibration Coefficients slopes from linear fit, gain ×8: ratio of slopes gain ×8/gain ×1: PreAmp Type 0.1 0.3 0.9 1.1 a8~0.25 ADC/DAC g = a8/a1= 1+ O(1%) Dispersion: ~5% in em (PreAmp Type A,E,F) ~10% in had (PreAmp Type D) Dispersion: ~0.5% in em (PreAmp Type A,E,F) ~1% in had (PreAmp Type D)

Slope correction to Z  ee pT1, pT2>20 GeV apply cell by cell calibration coefficients to em-objects improves resolution of z-peak doesn’t change position by constructions pT1, pT2>30 GeV back to back Events raw data  = 85.0 GeV  = 3.0 GeV slope corrections  = 85.1 GeV  = 2.7 GeV GeV 50 100

Timing corrections em channel had channel all linearity runs have been taken at fixed timing, but: slope depends on timing position but: same timing differences seen in physics and in pulser-calibration runs only timing differences with a pulser have to be corrected timing adjustment improved at the level of 10ns determining calibration coefficients at the signal maximum reduces dispersion, especially for hadronic channels

Calibration vs. Detector Signal time/ns simulation detector input calibration input difference in signal shape for detector and calibration signal calibration signal slower than detector reflection of calibration signal difference in response to detector parameters 400 cal/det-1 comparison of the variation in PreAmp input impedance (Zin): cal/det-1 (phys taken as reference at its signal max) stable point at max of calibration signal (B), although correction needed B time(ns)

Reflection Measurements determination of all other stable detector parameters from reflection measurements for all 55k channels Cdetector Cstrip Lstrip skin effect inner cryostat cable feed-through outer cryostat cable parameters extracted from fit: capacitance of D-Type detector channels

Signal shape comparison detector measured simulation em-channel time/ns time/ns em-channel calibration measured simulation But: signal about 20% slower from shaper output measurement in the detector comparing to simulation for both detector and calibration signals measurement and simulation in agreement for test bench measurements discrepancy in shape for hadronic signals studies of these effects ongoing

 - intercalibration N(Ei) = N(Eref) with divide each -ring of the calorimeter in its 64 -modules compare N(E0) = number of events with E>E0 S(E0)= sum of energy > E0 determine energy Ei in each module i, such as the N(Ei) = N(Eref) with evaluation criteria of method for data/MC - flatness: rms of the total energy distribution in each module for 1 -ring

method of Z-calibration determine di-electron mass in data and MC: fit a Breit-Wigner to the Z-peak region of the obtained distribution define calibration coefficients as: w.r.t the statistics, define various detector regions in  for the calibration maximize a likelihood function to determine the calibration coefficients

Scale Calibration with Zee ECN CC ECS 39 events 117 events 31 events calibration coefficients determined without corrections from online-calibration calibration coefficients derived for 3 cryostat regions, which restores Z-peak at expected value after online-corrections, calibration coefficients expected to be small

W e Candidates E/p ~ 1 in selected W sample with ET>25 GeV em objects with tack match el-id criteria EM cluster with SMT track W selection search for cluster track matching with global tracks (SMT+CFT) E/p ~ 1 in selected W sample with ET>25 GeV

Jet Energy Scale correct Jet Energy to the particle level Eoffset energy offset from underlying event, pile-up, noise determined from Min. Bias Events Rcalo calorimeter response using -jet events: Missing ET Projection Fraction Method Rcone energy contained in jet cone corrections from MC - energy in cones around the jet axis

JES - Calorimeter Response  jet DØ ideal calorimeter jet response (with calibrated ): jet response obtained from plate level MC: 90% for E<50GeV various parameterization models give similar response

Conclusions First online calibration of the new D0-calorimeter electronics determined no major scale corrections expected for em-objects after SCA non-linearity corrections dispersion for em-channels ~ 5%, hadronic channels ~10% understanding of signal shapes offline calibration procedures established Z-peak reconstruction E/p matching in W-events expected correction of JES at 10% level quantitative results after coherent propagation of online corrections