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