Z
ee
CDF Run II Silicon
John Zhou
Rutgers University
Run II!
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CDF Silicon Run II
Motivation:
tracking b quarks for
 top
 Higgs
 CP Violation
 Exotics

Run II as of end of
October
 Large fraction of data were
taken with silicon
 Achieving higher silicon
inclusion efficiency month
by month
CDF Run II Silicon– J.Zhou
11/19/2002
Silicon Overview
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8 Layers, 704 ladders, 722432 Chans
 Layer 00 (L00): 1 Single Sided layer
 SVXII: 5 Double Sided Layers
 ISL: 2 Double Sided Layers
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SVX-3 Chip
One of largest and most complex silicon
system ever built
CDF Run II Silicon– J.Zhou
11/19/2002
SVXII Barrels
o
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CDF Run II Silicon– J.Zhou
o
5 DS Layers (3 90 , 2 1.2 ),
2.5 < r < 10.6 cm, l = 0.9 m,
greatly enhanced coverage
360 ladders, 405504 Chan.
Standalone 3D tracking
“Displaced track” trigger
11/19/2002
Intermediate Silicon Layers (ISL)
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Linking COT to the SVX for
optimal tracking performance
Extends tracking to ||=2
o
2 DS 1.2 layers, r = 20,28 cm,
l = 1.9 m!
296 ladders, 303104 Chans
1m
1 meter
The ISL doubles the pseudorapidity range for b tagging and lepton id.
CDF Run II Silicon– J.Zhou
11/19/2002
Layer 00: Beampipe Layer
cables
SVX inner
bore

silicon
2.2 cm
C fiber
support
CDF Run II Silicon– J.Zhou
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Be beam
pipe
Cooling
tube
channel
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SS layer on beampipe
48 ladders, 13824 Chans
Increases IP (Impact
Parameter) resolution by
factor of 2 at pT = 1 GeV/c
11/19/2002
NSF at
More Silicon Projects
Power Supply
(Johns Hopkins)
SVT Board (Chicago)
Secondary Vertex
Trigger (Chicago)
Cables
(Johns Hopkins)
CDF Run II Silicon– J.Zhou
11/19/2002
NSF at
Silicon Vertex Detector
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Si Ladder inspection
(Rutgers)
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Si Burn-in System (Rutgers)
CDF Run II Silicon– J.Zhou
Sensor Testing
Beam Testing
Production Testing
Burn-in
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Calibration
Alignment
Monitoring
Si Burn-in Box
(Rutgers)
11/19/2002
Jumper HV Problem
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Fixed
Jumper did not hold high
voltage
 Takes signal, HV from phi
side to z side
 Signal/ground traces close
to HV traces
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Found after ~20 hours of
Burn-In
crucial test
Solution: Copper wire for
HV traces
Bus 4
HV
Bus 4*
CDF Run II Silicon– J.Zhou
11/19/2002
ISL Laser Surgery
cooling
problem
Unable to cool central part of ISL:
• Solid blockage experienced
• Appears at Al elbows (glue blockage
seen with boroscope)
• Laser successfully removed glue 9/12
lines so far, finish next long shutdown
CDF Run II Silicon– J.Zhou
11/19/2002
Wirebond Failures
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Loss of digital power on
13/360 SVXII Z sides
Hypothesis: fatigue from
Lorentz force
possible cause found
B
 Bond I orthogonal to B
 L1A rate  Resonance?
 Tests convincing

Ipp ~ 160 mA
Ongoing investigation
 Aging tests ongoing
 Reducing current and
catching warning signs
highest priority
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Protective measures
implemented
No new
failure
CDF Run II Silicon– J.Zhou
11/19/2002
Monitoring Silicon Performance
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Left: one chip of SVXII
ladder causing spikes in
ADC counts.
 Solution: mask the chip
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Bottom: stuck bit 0 on the
channel IDs on SVXII ladder
caused by optical
transmission.
 Solution: replace the optical
receiver
CDF Run II Silicon– J.Zhou
11/19/2002
Silicon Commissioning Summary
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Realistic Testing
 Power supply delivery
 ISL blocked cooling
 L00 noise
 Bit Errors
Reality Check: chip power
failure
 Beam splash
 High L1 rate
Despite daunting
challenges, currently 90%
of ladders are powered
and operating.
CDF Run II Silicon– J.Zhou
11/19/2002
Performance: Clusters
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Signal to
Noise > 10
 Single Hit
 > 99%
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Stability
 Pedestal
 Noise
1 ADC Pedestals
1 ADC Noise
Aug
Jul
Jun
May
Apr
Mar
Feb 02
CDF Run II Silicon– J.Zhou
11/19/2002
Calibration from Physics: J/
ICHEP 2002: c = 458 ± 10 ± 11 µm
CDF Run II Silicon– J.Zhou
11/19/2002
Future: Run IIb
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Radiation Damage  Replace L00,
SVXII (2005-2006)
SVX-4 Chip
 Improved rad hardness to 15 fb-1
 Easier to build-fewer different parts
 New SVX4 Chip
 DAQ etc mostly same as Run IIa
1st Electrical Stave
CDF Run II Silicon– J.Zhou
11/19/2002
Summary
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Silicon Commissioning near complete
Maintenance
 Detailed protection procedure in run control
 Getting to the small and subtle problems, solving them
 Lessons learned and passed on
 Still fair amount of work to do
• Most of the remaining problems are the hard ones…
• New things appear from time to time!

CDF Run II Silicon performing well
 Producing clusters and tracks
 Results already in Summer 2002, preparing for Winter now
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Run IIb is on the way
CDF Run II Silicon– J.Zhou
11/19/2002