D D DØ Silicon Microstrip Tracker for DØ Silicon Microstrip Tracker for runIIa runIIa Eric Kajfasz (CPPM/FNAL) - Breese Quinn (FNAL) Como, October 15, 2001 presented by Alice Bean (Kansas/FNAL) Design Production Assembly Readout Installation Commissioning Conclusions DØSMT DØSMT
DØSMT. DØ Silicon Microstrip Tracker for runIIa. Design Production Assembly Readout Installation Commissioning Conclusions. Eric Kajfasz (CPPM/FNAL) - Breese Quinn (FNAL) Como, October 15, 2001 presented by Alice Bean (Kansas/FNAL). RunIIa SMT Design. 12 F Disks. - PowerPoint PPT Presentation
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DDDØ Silicon Microstrip Tracker for DØ Silicon Microstrip Tracker for
runIIarunIIa
Eric Kajfasz (CPPM/FNAL) - Breese Quinn (FNAL)
Como, October 15, 2001
presented by Alice Bean (Kansas/FNAL)
Design Production Assembly Readout Installation Commissioning Conclusions
Kapton based flex circuits with0.2 mm pitch for chip mounting
Laminated to Beryllium substrateand glued to Silicon sensor
Connects Sensor to SVXII chips and SVXII chips to flex circuit via wire bonds(Al wedge bonding)
Connects to a Low Mass Cable which carries the signals out of the interaction region Be substrate
SVXIIE chips
9-chip HDI for 20 sensor
Bus control and power traces
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SVXIIe chip
1.2 um CMOS amplifier/analog delay/ADC chip fabricated in the UTMC rad hard process
Designed by LBL/FNAL
Some features:
128 channels
32 cell pipeline/channel
8-bit Wilkinson ADC
Sparsification
53 MHz readout
106 MHz digitization
6.4 x 9.7 mm2
About 85,000 transistors
Pipeline Control Logic
Analog Pipeline
128 channels
32 storage cells/channel
Inte
grat
ors
(128
cha
nnel
s)
AD
C C
ompa
rato
rs
Spa
rsifi
catio
n F
IFO
I/O
ADC ramp and counter
SVXIIFE SVXIIBE
Analog section Digital section
To
Sili
con
Det
ecto
r
To
Rea
dou
t S
yste
m
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SVXIIe chip
Externally programmed to achieve optimal performance for 132 or 396ns beam crossings and detector capacitances from 10 to 35pF (preamp bandwidth adjustment)
72 single-sided axial ladders2 sensors/ladderLocated on 1st and 3rd layer of 2 outer barrelsBe substrate, HDI and rohacell foam/carbon fiber rails glued on Silicon sensor
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Production: 6-chip ladders
144 double-sided double-metal axial/90° ladders
1 sensor/ladder Located on 1st and 3rd layer of
4 inner barrels
N-sideN-side P-sideP-side
Be substrate, HDI and rohacell foam/carbon fiber rails glued on Silicon sensor
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Production: 9-chip ladders
216 double-sided axial/2° ladders 2 sensors/ladder Located on 2nd and 4th layer all 6
barrels
N-sideN-side P-sideP-side
Be substrate, HDI and rohacell foam/carbon fiber rails glued on Silicon sensor
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Production: F-wedges
144 double-sided ±15° strips 6 (n) and 8 (p) readout chips 1 sensor/wedge Located on 12 F-disks
N-sideN-side P-sideP-side
Silicon sensor glued on HDI
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Production: H-wedges
96x2 back to back single-sided, ±7.5° strip angles
6-chip readout per side
2 sensors/wedge Be substrate and
HDI glued on Silicon sensor
Located on 4 H-disks
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Production: Sensor problems
Sensor lithography defectsA silicon manufacturing problem produced p-stop isolation defects in the 90° stereo ladders. This resulted in a 30% yield from the manufacturer.
Micro-discharge effect With negative p-side bias on double-sided detectors, we observed micro-
discharges producing large leakage currents and noise above a certain breakdown voltage.
The effect occurs along the edges of the p implants, where large field distortions and charge accumulations result from misalignment of electrodes
with implants.
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Production: Testing
Functionality TestDebug bad strips (broken capacitors), bonds, chips, etc.Determine the V-I characteristics of the sensors
Measure V-max p-side breakdown voltage (micro-discharge effect)
Burn-inBias the ladder or wedge and test the readout for 72 hoursMeasure pedestals, noise, gain and check sparse readout
LaserExpose biased detectors to a narrow laser scanMeasure the depletion voltage and leakage currents and identify dead channels
Readout tested again after the detector is mounted on a barrel or disk
Counting HouseCounting HouseCounting HouseCounting House
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SMT Readout: Electronics
Interface Boards8 crates (144 boards) located inside the detector volumeRegenerates signalsSVX monitoring and power managementBias voltage distribution
SEQuencers6 crates (120 boards) located on the detector platformUse SVX control lines to actuate acquisition, digitization and readoutConvert SVX data to optical signals
A ½ cylinder of 3 barrels and 6 F disks was inserted into each end of the CFT bore
H Disk installation was completed on 2/6/01
The cabling (~15,000 connections) and electronics installation was completed in May 2001
Fiber Tracker
Low Mass Cables
High Mass Cables
SMT
Interface Boards
Calorimeter
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Commissioning: Status
The entire detector has been connected and poweredThe 30% glycol + water coolant is refrigerated at –10 degC (=> detectors run between –5 and 0 degC)~15% of the devices are not in the readout:
10% ladders, 18% F wedges, 20% H wedgesProblems could be with boards, cables, connectors, chips, etc. We will debug each of them during the October/November shutdown, and expect to recover at least half of them.
Currently collecting calibration, alignment and commissioning data
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Commissioning; Event Display
Online SMT event display
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Commissioning: Monitoring
Online event monitoring program
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Commissioning: Charge Collection
A cluster is defined as a contiguous sequence of strips with
Each strip 6 ADC counts
Cluster 12 ADC counts
1 MIP ~ 25 ADC counts
One can play on:Timing settings, i.e. the delay of the integration window w.r.t. the beam crossing
Preamp bandwith (pabw)
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Commissioning: Timing and S/N
Higher preamp bandwith does not significantly reduce noise on n-side
= 4x132ns + 1x18ns + 0x2ns
Highest value smallest bandwith
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Commissioning: Calibrations
SMT pedestal, noise and gain measurements are taken using SDAQ. Pedestal and noise measurements are used to calculate the threshold per chip to be used in sparse read out
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Barrel cluster charge vs eta
MC
data
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6-chip ladder n-side cluster size fraction vs eta
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SMT & CFT Track Matching
Tracks were found separately in the SMT and the Central Fiber Tracker (CFT)
SMT tracks were extrapolated to the CFT at which point the track offsets were measured
Magnet off data
r = -3 36 m
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SMT-CFT primary tracks
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Conclusions
Design/ProductionExperience with double-sided detectors has led to the decision to use single-sided silicon for the upgrade.
Should work towards simpler designs in the future. For example, using 6 different sensor types resulted in extensive logistical complications.
Had to overcome numerous vendor related problems for HDIs, Silicon Sensors, jumpers, low mass cables …
Assembly/InstallationFirst alignment results show that the DØ SMT was assembled and installed very well.
The installation in the D0 detector went rather smoothly. The biggest challenge to overcome was the lack of real estate. The D0 detector, when first designed, was unfortunately not designed with a Silicon detector in mind
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Conclusions
CommissioningThe SMT was the first major DØ Upgrade detector system fully operational for Run 2a. More than 85% of the channels were available for readout on startup, and most of the remaining channels will be debugged and recovered by November.Calibrations and first look at physics show that we understand our detector.The offline software is debugged at the same time as the hardware. Now that they are both reasonably stable, we can start systematic studies.The detector should be commissioned by the end of the year.We are eager to start doing good physics with it.
GeneralConstruction and commissioning of the SMT has been an adventure full of challenges. But thanks to the relentless efforts of many physicists, engineers and technicians, D0 has now a vertex detector to play with.We had so much fun building this detector for run 2a that we are already planning to build a completely new Silicon Microstrip detector for run 2b (see Alice’s talk)