CDF Run II Silicon John Zhou Rutgers University Z ee.
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Transcript of CDF Run II Silicon John Zhou Rutgers University Z ee.
CDF Run II SiliconJohn Zhou
Rutgers University
Z ee
CDF Run II Silicon– J.Zhou 11/19/2002
Run II! 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
8 Layers, 704 ladders, 722432 Chans Layer 00 (L00): 1 Single Sided layer SVXII: 5 Double Sided Layers ISL: 2 Double Sided Layers
One of largest and most complex silicon system ever built
SVX-3 Chip
CDF Run II Silicon– J.Zhou 11/19/2002
SVXII Barrels 5 DS Layers (3 90o, 2 1.2o),
2.5 < r < 10.6 cm, l = 0.9 m, greatly enhanced coverage
360 ladders, 405504 Chan. Standalone 3D tracking “Displaced track” trigger
CDF Run II Silicon– J.Zhou 11/19/2002
The ISL doubles the pseudorapidity range for b tagging and lepton id.
Linking COT to the SVX for optimal tracking performance
Extends tracking to ||=2 2 DS 1.2o layers, r = 20,28 cm,
l = 1.9 m! 296 ladders, 303104 Chans
1 meter
Intermediate Silicon Layers (ISL)
1 m
CDF Run II Silicon– J.Zhou 11/19/2002
Layer 00: Beampipe Layer
SS layer on beampipe 48 ladders, 13824 Chans Increases IP (Impact
Parameter) resolution by factor of 2 at pT = 1 GeV/c
Be beam pipe
2.2 cm
silicon
cables SVX inner bore
Cooling tube channel
C fiber support
CDF Run II Silicon– J.Zhou 11/19/2002
SVT Board (Chicago)
More Silicon Projects
Cables (Johns Hopkins)
Secondary Vertex Trigger (Chicago)
NSF atPower Supply (Johns Hopkins)
CDF Run II Silicon– J.Zhou 11/19/2002
Si Ladder inspection (Rutgers)
SV
T B
oard
(U
C)
Si Burn-in System (Rutgers)
Silicon Vertex Detector
Si Burn-in Box (Rutgers)
NSF at
Sensor Testing Beam Testing Production Testing Burn-in
Calibration Alignment Monitoring
CDF Run II Silicon– J.Zhou 11/19/2002
Jumper HV Problem Fixed
Bus 4HVBus 4*
Jumper did not hold high voltage Takes signal, HV from phi
side to z side Signal/ground traces close
to HV traces Found after ~20 hours of
Burn-In crucial test Solution: Copper wire for
HV traces
CDF Run II Silicon– J.Zhou 11/19/2002
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
cooling problem
ISL Laser Surgery
CDF Run II Silicon– J.Zhou 11/19/2002
Wirebond Failures possible cause found Loss of digital power on
13/360 SVXII Z sides Hypothesis: fatigue from
Lorentz force Bond I orthogonal to B L1A rate Resonance? Tests convincing
Ongoing investigation Aging tests ongoing Reducing current and
catching warning signs highest priority
Protective measures implemented No new failure
B
Ipp ~ 160 mA
CDF Run II Silicon– J.Zhou 11/19/2002
Monitoring Silicon Performance
Left: one chip of SVXII ladder causing spikes in ADC counts. Solution: mask the chip
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
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.
Silicon Commissioning Summary
CDF Run II Silicon– J.Zhou 11/19/2002
Performance: Clusters
Signal to Noise > 10 Single Hit
> 99%
Stability Pedestal Noise
Feb
02
Mar
Ap
rM
ay
Jun
Jul
Au
g
1 ADC Pedestals
1 ADC Noise
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 Radiation Damage Replace L00,
SVXII (2005-2006) 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
SVX-4 Chip
CDF Run II Silicon– J.Zhou 11/19/2002
Summary
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
Run IIb is on the way