the cms silicon strip tracker

The CMS Silicon Strip Tracker

Carlo CivininiINFN-Firenze

On behalf of the CMS Tracker Collaboration

Sixth International "Hiroshima" Symposium on the

Development and Application ofSemiconductor Tracking Detectors

Carmel Mission Inn, California September 11-15, 2006

Pixel Detector

Inner Barrel (TIB)

Inner Disks (TID)

Outer Barrel (TOB)

End Caps (TEC)

The CMS Silicon Tracker

•4 layers in TIB

•6 disks in TID

•6 layers in TOB

•18 disks in TECS. Mersi

1.2 m

2.7 m

13.09.2006 Carlo Civinini INFN-Firenze STD06 3

Silicon Strip Modules

Kapton Bias Circuit

Carbon Fiber/Graphite Frame Silicon Sensors

Front-End Hybrid

Pitch Adapter

APV and control chips

Kapton tails

• TIB Module

29 different Module Flavours

All single sided sensors double sided detectors are realized gluing back to back two single sided modules


Sensors• p on n• 6” wafers• Inner region: low

resistivity 1.5-3.5 kcm, thin 320 m

• Outer region: higher resistivity 3.5-7.5 kcm, thick 500 m

• Polysilicon resistorBiasing

• AC-coupled Al readout strips

• <100> Si orientation• Metal overhang on

implant strips• Single sided

6.136 Thin wafers 6.136 Thin detectors (1 sensor)

18.192 Thick wafers 9.096 Thick detectors (2 sensors)More than 200 m2 of Silicon

Surface16 Sensor Designs

This room is 180 m2


Front-end Electronics

APV25

PLL

MUX

DCU

12 hybrid designs9.648.128 Strips

electronics channels75.376 APV chips26.000.000 Bonds

37 000 analog optical links

3000 km optical fibresKapton Multilayer Hybrid circuit


Front-end Electronics• APV25• Radiation tolerant 0.25 m CMOS technology• Charge sensitive amplifier with =50 ns, CR-RC shaper,

192 cell pipeline (4.8 s deep) per channel• 128 channels multiplexed to 1 analog output• Operation modes: Peak mode (1 sample, =50 ns);

Deconvolution mode (weighted sum of 3 samples, =25 ns) High Luminosity

• MUX• 2 APV25 chips outputs onto a single differential line• PLL• Decodes clock & trigger signals + delay adjusts• DCU • Slow control data 12 bit ADC (onboard temperatures,

leakage current, low voltages)• AOH• Analog opto-hybrid, converts the front-end analog output

current to laser light• All functional parameters of these devices can be

down/uploaded by mean of I2C bus


Module Test

• The 15232 (+spares) produced modules have been tested to spot possible problems and each strip has been characterized in term of noise, short, open, pinhole etc…

• Information about module quality has been stored in a production database

• A large fraction of production has been also thermally stressed before integration on the mechanical structures


Module Test

TOB noise distribution for 4-chip and 6-chip modules 400V bias (30% production)

opensnoisy

C. Marchettini


Module Production Summary

Percentage of bad strips on good modules at level of 0.05% - 0.1%

Modules produced

Good after assembly*

Bad* % good

TIB/TID 3945 3810 135 97%

TOB 5434 5348 86 98%

TEC 7228 6761 467 94%

Total 16607 15919 688 96%

* Sept. 4st 2006 (Includes also module repair)

M. Krammer


TIB Integration

… how to assemble a piece of Tracker(16 half shells)


TIB Integration

• Mechanical structure (with cooling pipes and precision ledges)

• Mount Analog OptoHybrids and Mother Cables

• Modules installation• Tests


Mechanical Structure

Temporary fibreHolders

Carbon fibreStructural part

PT1000 TemperatureProbes

Cooling pipes

Cooling precision Ledges

Half shell of half barrelTIB+ or TIB-

Depending on the side of the interaction point

Plus Minus


AOH and MC Mounting

2 meters long pigtail optical fibres

Analog electrical signals from the module

Mother Cable:Kapton circuit which provides Modules with power, clock, trigger and I2C data

Analog OpticalHybrid


Modules

Precision InsertPrecision Insert

• Each module has been mounted by hand on the mechanical structure

• Double sided modules, because of their complexity, need a simple mechanical tool to guide the operator’s hand

• The precision is anyway defined by the mechanics, no loss of precision or reproducibility in this operation

• Very rare accidents because of handling…


Tests

• After each single module has been mounted a fast connectivity test is done (I2C bus scan, module identity check)

• When a string of modules (3) is mounted a deep test is performed: readout timing and optoelectronics optimization then pedestals and noise @ 400V bias


Cumulative noise

ADC Counts

Layer 4 Backward upnoiseDistribution

Deconvolution400V bias

Opens (0.03%)

2.1 is the cut usedDuring module productionTest to flag a noisy strip

C. Genta


Full of modules…


Burn in

• All TIB half shells and TID disks were checked for possible weak components fail and for temperatures and noise behaviour

• A structure is fully powered and readout during this test.

• Runs are taken both at room temperature and at cold (C6F14 @ -25oC and sensors @ -15oC), peak and deconvolution mode

• Same sequence as integration: timing and optogain optimization then pedestals and noise run


Burn-in Noise

Noise distribution atBurn-in of Layer4 backward up

Deconvolution 400V Bias

ADC countsA. VenturiM. Vos


Building the TIB+The TIB half shells are coupled together and then inserted oneinto the other (4,3,2,1 sequence) to form the barrel

T. Lomtadze & A. Basti


TIB+Seen from the interactionpoint

R. Dell’Orso


Conclusions

• The CMS Silicon Strip Tracker Collaboration has finished the components production– O(105) complex objects (modules, electronics boards,

mechanical parts, cables, fibres, etc.) tested

• The integration phase is now well advanced (an O(105) pieces puzzle) and the different sub-detectors (TIB/TID, TOB, TEC) will be joined together in the coming months

• Then commissioning and finally Physics…

the cms silicon strip tracker

Documents

sided detectors

thick detectors

thick wafers

chip modules

analog optical links

tib6 disks

tob18 disks

analog outputoperation