Transcript Calorimeter Calibration

Calorimeter Calibration
• Electronics Calibration
• Online Calibration Software
• Database handling
• Offline Calibration
Slides contributed from: U. Bassler, M. Bhattacharjee, L. Groer, F. Machefert, S. Muanza
Bob Olivier NIU
6/22/00
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Electronics Calibration
Calorimeter Electronics
Trig. sum
Bank 0
Calibration
Calorimeter
SCA (48 deep)
Preamp/
Driver
Filter/
Shaper
x1
x8
SCA (48 deep)
BLS
SCA
Output
Buffer
SCA (48 deep)
SCA (48 deep)
Goals:
Bank 1
•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
Bob Olivier NIU
6/22/00
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Calibration System
(LAL Orsay, LPNHE Paris)
6 commands (3x2)
96 currents
PIB
Trigger
Pulser
Power supply
switch
2 Fanout
(2x3x16 switchs)
Preamps box
12 units for calorimeter + 1 for ICD
 smallest unit to be calibrated: 1 ADC crate
Bob Olivier NIU
6/22/00
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Calibration System: Pulser + Fanout
Pulser:
• current generator
• command trigger
• pulse shape controller
Active FanOut:
“pulse formation” :
receiving a
command signal,
switch is opened
Bob Olivier NIU
6/22/00
 Hardware installation nearly completed
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Calibration System:
Pulser Interface Board
• interface epics/pulser
• produces event header
• automated calibration procedure
Bob Olivier NIU
6/22/00
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Pulser Interface Board
GUI
RAM
Pulser 1 Pulser 13
L3
Pulser 1 Pulser 13
Request
Status
CPU
Trigger
Serial
Counter Port
ECL/TTL
Pulser
Bob Olivier NIU
6/22/00
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
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Software: Pulser Communication
GUI for pulser setting
TAKER
COOR
data block
structure
COMICS
EPICS
VBD
L3
Bob Olivier NIU
6/22/00
PIB
Hardware database
VME address of
RAM registers
program and
protocol structure
event header
PULSER
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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
Bob Olivier NIU
6/22/00
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Calibration Data Flow
CALIBRATION PROCEDURES: 2/3 times a week
• pedestal runs: ped, 
• pulser runs: gain1, gain8
after validation
ONLINE DATABASE:
• constants ordered
copy
by crate#, card#, channel #
BLS:
• integers for 0suppression
•constants updated
Bob Olivier NIU
6/22/00
OFFLINE DATABASE:
• optimized format for reco
possible
L3:
• “golden sample”
RECONSTRUCTION:
• 0-suppression parameters
TRIGGER:
• no calibration
• channel and gain intercalibration
• constants updated
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Software for DAQ Commissioning
Version of Calibration cal_elec runs on online HOST
(since Feb, 2000 part of commissioning milestone)
• grabs data from distributor
• calculates , /channel
• reports running , /channel
• prints status report
• being used to debug CAL crates 10 & 11
Run type: pedestal
Sigma tails from preamp
capacitance
Bob Olivier NIU
6/22/00
10
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)
Bob Olivier NIU
6/22/00


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Calibration in the Reconstruction
raw data chunk: packed format
ADC hits, crate #, card #, tower #, layers#
cal_unpack_package
FE data chunk: unpacked format
ADC hits, crate #, card #, tower #, layers#
cal_calib_package
Calibrated data chunk: keeps ordering
energies, crate #, card #, tower #, layers#
cal_geom_package
Reconstructed data chunk: physics units
energies, , 
Bob Olivier NIU
6/22/00
OFFLINE
DATABASE:
• crate #, card #,
tower #, layers#
• ped, , 0-suppr.,
gain1, gain8
calibration manager:
access to database for
all subdetectors
cal_calibrator:
fills calorimeter
calibration classes
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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
Bob Olivier NIU
6/22/00
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Offline Calibration
Intercalibration:
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Bob Olivier NIU
6/22/00
Phi Symmetry
No beam polarization => symmetry in 
Run I: symetrize energy flow in 
Could use W   e  e 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
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EM Energy Scale
Resonances:
• Using Z  e  e  sets the absolute energy scale
• Check the results with other known resonances:
 0   ,
Method:
•
•
J / or   e  e 
Etrue  Emeas  
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
Bob Olivier NIU
6/22/00
15
Jet Energy Scale
Compare two processes usable for JES calibration:
  jet
vs
Z  jet (Z  e e /     )
Aim:
• Z  jet complement   jet at high Et
• MC independent cross-check
Advantages:
incl. X-sect (nb)
Run I
• very low background
Photon + jet
200
• harder Et spectrum
Z + jet
1.8
Drawbacks:
•lower statistics
(GeV)
Mean boson pT
Bob Olivier NIU
6/22/00
Run II
229
2.2
RMS boson pT
Photon + jet
14.2
5.7
Z + jet
22.5
16.6
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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:
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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
Bob Olivier NIU
6/22/00
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