The CMS Silicon Strip Tracker

1. The CMS Silicon Strip Tracker Carlo Civinini INFN-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

2. Pixel Detector Inner Barrel (TIB) Inner Disks (TID) Outer Barrel (TOB) End Caps (TEC) The CMS Silicon Tracker 1.2 m 2.7 m • 4 layers in TIB • 6 disks in TID • 6 layers in TOB • 18 disks in TEC S. Mersi

3. Front-End Hybrid APV and control chips Kapton tails Pitch Adapter Kapton Bias Circuit Carbon Fiber/Graphite Frame Silicon Sensors Silicon Strip Modules • TIB Module 29 different Module Flavours All single sided sensors  double sided detectors are realized gluing back to back two single sided modules Carlo Civinini INFN-Firenze STD06

4. Sensors • p on n • 6” wafers • Inner region: low resistivity 1.5-3.5 kWcm, thin 320 mm • Outer region: higher resistivity 3.5-7.5 kWcm, thick 500 mm • Polysilicon resistor Biasing • 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 Surface 16 Sensor Designs This room is 180 m2 Carlo Civinini INFN-Firenze STD06

5. Front-end Electronics 12 hybrid designs 9.648.128 Strips  electronics channels 75.376 APV chips 26.000.000 Bonds 37 000 analog optical links 3000 km optical fibres APV25 PLL MUX Kapton Multilayer Hybrid circuit DCU Carlo Civinini INFN-Firenze STD06

6. Front-end Electronics • APV25 • Radiation tolerant 0.25 mm CMOS technology • Charge sensitive amplifier with t=50 ns, CR-RC shaper, 192 cell pipeline (4.8 ms deep) per channel • 128 channels multiplexed to 1 analog output • Operation modes: Peak mode (1 sample, t=50 ns); Deconvolution mode (weighted sum of 3 samples, t=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 Carlo Civinini INFN-Firenze STD06

7. 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 Carlo Civinini INFN-Firenze STD06

8. Module Test opens noisy C. Marchettini TOB noise distribution for 4-chip and 6-chip modules 400V bias (30% production) Carlo Civinini INFN-Firenze STD06

9. Module Production Summary M. Krammer Percentage of bad strips on good modules at level of 0.05% - 0.1% * Sept. 4st 2006 (Includes also module repair) Carlo Civinini INFN-Firenze STD06

10. TIB Integration … how to assemble a piece of Tracker (16 half shells) Carlo Civinini INFN-Firenze STD06

11. TIB Integration • Mechanical structure (with cooling pipes and precision ledges) • Mount Analog OptoHybrids and Mother Cables • Modules installation • Tests Carlo Civinini INFN-Firenze STD06

12. Mechanical Structure Temporary fibre Holders Carbon fibre Structural part PT1000 Temperature Probes Cooling pipes Cooling precision Ledges Plus Minus Half shell of half barrel TIB+ or TIB- Depending on the side of the interaction point Carlo Civinini INFN-Firenze STD06

13. AOH and MC Mounting Mother Cable: Kapton circuit which provides Modules with power, clock, trigger and I2C data 2 meters long pigtail optical fibres Analog Optical Hybrid Analog electrical signals from the module Carlo Civinini INFN-Firenze STD06

14. Modules • 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… Precision Insert Precision Insert Carlo Civinini INFN-Firenze STD06

15. 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 Carlo Civinini INFN-Firenze STD06

16. Cumulative noise Layer 4 Backward up noise Distribution Deconvolution 400V bias 2.1 is the cut used During module production Test to flag a noisy strip Opens (0.03%) ADC Counts C. Genta Carlo Civinini INFN-Firenze STD06

17. Full of modules… Carlo Civinini INFN-Firenze STD06

18. 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 Carlo Civinini INFN-Firenze STD06

19. Burn-in Noise Noise distribution at Burn-in of Layer4 backward up Deconvolution 400V Bias A. Venturi M. Vos ADC counts Carlo Civinini INFN-Firenze STD06

20. Building the TIB+ The TIB half shells are coupled together and then inserted one into the other (4,3,2,1 sequence) to form the barrel T. Lomtadze & A. Basti Carlo Civinini INFN-Firenze STD06

21. TIB+ Seen from the interaction point R. Dell’Orso Carlo Civinini INFN-Firenze STD06

22. 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… Carlo Civinini INFN-Firenze STD06