Calorimeter: Electronics Upgrade

1
Calorimeter Electronics Upgrade

• 55k channel Ur/liq. Argon calorimeter
• Run II upgrade
• replacement of electronics to accommodate faster
  bunch crossings
• 55k dual FET PreAmps
• 23k Switch Capacitor Arrays (SCA) on
  1200 BaseLineSubtraction (BLS)-boards
• 50 bad channels (0.1)

Trig. sum
Bank 0
Calibration
electronics readout chain
SCA (48 deep)
SCA (48 deep)
x1
Filter/ Shaper
Output Buffer
Preamp/ Driver
BLS
SCA
x8
Calorimeter
SCA (48 deep)
SCA (48 deep)
Bank 1
2
Calorimeter Commissioning
STATUS at Run-Start (March 01)

• channel debugging during shutdown periods
• october shutdown 240 channels fixed, 40
  definitily broken
• Many helped
• U. Bassler, G. Bernardi, F.
  Beaudette, S. Beauceron,
• M. Bhattacharjee, V. Bhatnagar,
  L. Duflot, T. Eltzroth, S. Fu, M. Gao, L.
  Groer, R. Hauser, M. Hohlfeld, B.
  Kehoe, B. McCarthy, N. Parua, M.
  Ridel, G. Sajot, D. Schamberger, M.
  Tuts, R. Zitoun, V. Zutshi

3
SCA - details
1 SCA chip 12 SCA channels 12x48 SCA cells
down

• gain 1 and 8 in L1SCA
• gain readout automatic (normal), forced (x1
  or x8)
• toggling between up-down L1SCAs to allow
  read/write
• dual mode same time sample written in 2
  different locations (L1 or L2)
• triple mode readout on peakearlylate time
  samples

Mean value
4
SCA debugging
Bad L2 SCA cells
behavior of good SCA
L2
Mean value (1 channel)
Bad L2 SCA(?)
about 60 channels still to be changed!
Cell number
5
Calorimeter Timing
Detector PreAmp-Boxes

• timing w.r.t accelerator
• done during 1?8 strores

jumpers/ BLS crate 5ns
cable length fixed
sampling time by RF-bucket in FPGA
MCH ADC cards
Platform BLS cards
delays/ trigger tower
MCH Timing Control Boards
MCH Trigger boards
scl-cable length adjustable 10ns
MCH Trigger framework
6
Trigger/Read Out timing

• flash ADC Read Out adjusted to peak of the
  Trigger Pickoff
• measurements done for a sample of em/had channels
  in CC
• same value used everywhere

• systematic adjustment comparing L1Cal-Read Out
  by varying the Trigger by /- 1 RF-bucket
• final L1Cal trigger Read Out installed
  systematic studies forthcoming

7
Timing studies
using triple sampling runs all crates timed in
at 10ns
late
nominal
early



early/ nom.
Spice model ?1.3
... Shaper on scope
?0.69

• But
• pedestal values of early/late sampling different
  than nominal
• additional capa on each BLS-board removed the
  effect
• Signal shape is not consistent between
  shaper-meausrements on scope, triple sampling
  data and spice model

late/ nom.
?0.77
8
Initial Scale Estimation
Preamps with 5 or 10pF feedback capacitance
PreAmp output same than in RunI
shaping signal ? 2/3 intial RunI signal size
digitization to corrected ADC counts
independent of gain1/8 path
terminated cable signal/2 PreAmp Driver signal ?
3
inject pulser signal
compare expected number of ADC counts with
measured
measure signal with scope
different Detector Capacitances according to cell
type same than in Run I
9
Pulser Scale verification

• DAC25k shaper Output 2.2V ? SCA (after gain
  selection) 1.1V
• Electronics Design 4V in SCA 32000 Adc
  counts
• estimation 25k 1.1V 8800 Adc Counts
• ADC measurement
• DAC25k ADC counts 6355
• reason
• 2 resistors inverted on BLS card schematic
• overall scale factor (1.4) applied in software
• scale estimation at 10

10
Calorimeter W/Z events
Z ?ee candidate 2 EM objects, ET gt 20
GeV, isolation and shower shape cuts
m(e,e) L0.7pb-1
DØ
DØ
mT(e,n) L0.7pb-1
MZ
un-calibrated energies
un-calibrated energies
invariant mass (GeV)
transverse mass (GeV)
11
Calorimeter jet events
?-jet event ET?27 GeV em-fraction 0.9
2-jet event ETjet1230 GeV, ETjet2190GeV
Etjet24GeV em-fraction 0.5
DØ
Run I- jet corrections
DØ
0.7 cone
12
Waveform Measurements
Termination Resistor check on PreAmp Bords
missing 3321?

• measurement of calibration pulse shape at
  PreAmp-Board Input
• determine uniformity (correction factors) for
  final calibration signal
• check out of calibration system black cables,
  switches, PreAmpBoards

13
Waveform Systematics
input channel
switch number
PreAmp back-plane module
slot
10 variation
input channel
switch

• 3 systematic effects test card/input channel,
  pulser switch, back-plane trace (slot)
• amplitude, time 10 sensitive to slot
  parasitic capacitance
• integral more sensitive to switch
• But wiggles in waveform require fit to
  reasonably study behavior

4 variation
14
Online Calibration
Online calibration R. Zitoun L3fCalCalibTool
produces ?,? for pedestals and pulsers

• validation N. Parua
• check of pedestal values
• applies values and check of occupancy

• shift monitoring
• occupancy checks during data taking

Calibration Manager

extraction tables downloaded in ADCs bad cell
lists
Online database pedestal and pulser value
tables
Unpacking T. Kurca Apply in reconstruction
Offline database pedestal and gain tables
15
New database design
16
this is hopefully the past!

• Improved hardware
• Better Monitoring tools
• Shifters! Grenoble, Lyon, Orsay, Paris

Calorimeter Information for each
Run www-d0nline.fnal.gov/groupes/calorimeter/runs
ummary.html Calorimeter Online/Offline Meetings
Tuesday 1000 am 9th circle www-d0.fnal.gov/d0upg
rad/d0_private/software/calorimeter/meetings.html
? contains an summary of the calorimeter status
for each week