1. - 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

2. 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

3. 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

4. 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%)

5. 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

6. 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

7. Pulser & Fan-out
switches

8. 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%

9. 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

10. 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

11. 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

12. 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

13. 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

14. Effect of SCA-non linearity
~Energy/GeV
0.25 ADC count/MeV 4
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

15. 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)

16. 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

17. 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

18. 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)

19. 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

20. 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

21.  - 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

22. 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

23. 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

24. 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

25. 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

26. 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

27. 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