1. Commissioning and performance of the CMS silicon microstrip detector
Regina Demina
University of Rochester
September 30, 2009
RD09 - 9th International Conference on Large Scale Applications
and Radiation Hardness of Semiconductor Detectors, Florence, Italy
CMS week Regina Demina University of Rochester

2. From concepts to reality

3. Regina Demina University of Rochester
CMS Tracker
CERN/LHCC 98-6, CMS TDR 5, 15 April 1998 – Silicon Microstrips and MSGC tracker for CMS
Addendum   (CERN/LHCC , CMS TDR 5 Addendum 1, 21 February 2000) - all SiMstrip tracker
10 M strips
Next largest Si system - D0 SMT <~1M channels
80 k readout chips
26 M wire-bonds
200 m2 of sensors
100 kg of silicon
Choices were made to
simplify the system
compared to D0/CDF
Run 2 devices
Single sided silicon
Analog chip
Optical readout
5.4 m
2.4 m
Inner Barrel & Disks
(TIB & TID)
Pixels
volume 24.4 m3
running temperature – 20 0C
September 30, 2009
Regina Demina University of Rochester

4. Regina Demina University of Rochester
Industry involvement
Hamamatsu Photonics, Japan. Supply of silicon sensors IBM Microelectronics. Delivery of 0.25µm CMOS electronics, APV25. Planar Systems, Finland. Aluminium on glass pitch adapters. Reinhard Microtech, Switzerland. Aluminium on glass pitch adapters Hybrid SA, Switzerland. Assembly of tracker hybrids. Cicorel, Switzerland. Manufacture of kapton hybrids
Kapsch, Austria. Manufacture and assembly of TEC and TOB optohybrids
G&A, Italy. Manufacture and assembly of TIB Optohybrids
COI, USA. Manufacture of Carbon Fiber Frames for Tracker Modules
eXception EMS , UK. Manufacture of Front End Drivers.
ST, Italy. Manufacture of pigtailed laser assemblies for optical links
NGK, Japan. Manufacture of analogue optical receivers,
CAEN, Italy. Manufacture of power supplies
Adapt, Germany. Cable assemblies
September 30, 2009
Regina Demina University of Rochester

5. CERN TK ASSEMBLY TOB assembly TIB/D assembly TEC assembly TEC assembly
Frames:
Sensors:
Hybrids:
Pitch adapter:
Hybrid:
Brussels
factories
Strasbourg
Brussels
CF carrier
CERN
Pisa
Sensor QAC UR
Perugia
Wien
Louvain
Karlsruhe
Strasbourg
Module
assembly
Brussels
UCSB
FNAL
UCSB
Perugia
Bari
Wien
Lyon
Bonding &
testing
FNAL
UCSB
Padova
Pisa
Torino
Bari
Firenze
Wien
Zurich
Strasbourg
Karlsruhe
Aachen
UCSB
Integration
into
mechanics
ROD INTEGRATION
TIB/TID INTEGRATION
Louvain
PETALS INTEGRATION
Aachen
FNAL
UCSB
Pisa
Brussels
Lyon
Strasbourg
Karlsruhe
TOB
assembly
TIB/D
assembly
TEC
assembly
TEC
assembly
Sub-assemblies
At CERN
Pisa
Aachen
Karlsruhe . --
> Lyon
TK ASSEMBLY
At CERN

6. Regina Demina University of Rochester
Production cycle
Sensor probing
Assemble modules
Test modules
Multi-rod burn-in
Single rod test
Thermal test modules
Shipment to CERN
Rod reception
Tracker integration
and commissioning
September 30, 2009
Regina Demina University of Rochester

7. Integration and commissioning
Delivery at CERN of the TIB/TID+ 31 May 2006
Completion of TOB assembly Aug 2006
Delivery of TEC+ to CERN Jul 2006
Magnet test and cosmic challenge Jul-Sep 2006
133 modules (24 TOB, 34 TEC, 75 TIB)
Took cosmics data with new Event Data Model/CMSSW framework
25 M events with Tracker and ECAL
Data taking efficiency close to 90%
Stand alone tracker commissioning Sep 2006
Establish DAQ and DCS stable operation
Commission sector of the Tracker (~20%) with realistic cabling
Track cosmics, commission hardware and software
Silicon Tracker installation in CMS 16 December 2007
CRAFT08 – October 2008
Most of the analysis is complete and 3 papers are prepared
Most results in this talk is based on these data
CRAFT09 – July Aug 2009
Analysis in progress
September 30, 2009
Regina Demina University of Rochester

8. Regina Demina University of Rochester
CRAFT08
Tracker Operation in CRAFT08 – Oct/Nov 2008
First full commissioning of the Tracker (not all final or fully optimized conditions)
Coolant temperature = 13° (4° in CRAFT09)
Strips in peak mode of the APV Front End chip
Higher S/N mode but pulse above threshold for 7 bunch crossings
deconvolution mode designed to minimize BX pile-up used in CRAFT09
Data taking took place from 15/10/08 to 11/11/08 (27 days)
Global data taking ~ 75%
Tracker in ~ 90% of the Global data taking with
Working fractions:
TIB/TID TOB TEC+ TEC -
96.7% 98.3% 99.2% 98.3%
Some of the missing components were recovered during shut down for CRAFT09
September 30, 2009
Regina Demina University of Rochester

9. Tracker status: cooling
Refurbished and re-commissioned the cooling plants
Nov 08: Total leak rate (SS1+SS2) when operations stopped in Nov 08: ~ 45 Kg/day (and growing….)
May 09: Total leaks on SS1 – virtually zero
June 09: On SS2: The leak rate is very low (~5kg/day) excluding 1/180 cooling loops (can be off)
The leak for SS2 has been identified to be inside the Tracker and it' s thus not fixable at the moment
SS1 final distribution
assembly completed
Carefully recovered & repaired services at PP1, fixed the sealing.

10. Regina Demina University of Rochester
Working fractions
September 30, 2009
Regina Demina University of Rochester

11. Signal to noise in CRAFT08
On track strip clusters Signal to Noise ratio (S/N).
The signal Most Probable Value is obtained in peak mode of the read-out chip and is corrected for track angle effect
TOB thick sensors : S/N = 31-32
TIB/TID thin sensors : S/N = 25/29
TEC thin sensors : S/N = 27-30
TEC thick sensors : S/N = 31-36
September 30, 2009
Regina Demina University of Rochester

12. Cluster properties: crosstalk
Cross talk measured using virgin raw data by analyzing the charge distribution for tracks perpendicular to sensor surface :
Charge Ratio = (Qmax±1)/Qmax = x/(1-2x)
X – cross talk value
September 30, 2009
Regina Demina University of Rochester

13. Regina Demina University of Rochester
Lorentz angle
Lorentz Angle (θL) method :
- Per module :
tan(θL) = minimum of fit of module
cluster width
- Average layer values : μH = tan (θL)/B
- μH (TIB 300 μm sensors) = 0.018
- μH (TOB 500 μm sensors) = 0.023
September 30, 2009
Regina Demina University of Rochester

14. Tracker performance compared to Monte Carlo
Cluster properties in Monte Carlo well tuned to represent performance on data
Achieved impact parameter resolution for cosmic tracks of 29 um, expected given perfect alignment –28.8 um

15. Regina Demina University of Rochester
Tracker efficiency
Tag and Probe method
• Tag : Stand alone muons
•|dz|< 30cm, |dxy|< 30cm, |eta|< 1, 0.5 < |phi|< 2.5
(at point of closest approach)
• Probe : Tracker muons
Single hit efficiency for good modules >98%.
Efficiency of track reconstruction >99%, matches well MC prediction
September 30, 2009
Regina Demina University of Rochester

16. CRAFT09 Signal to noise ratio
Events collected: ~480M
~ 12 M tracks (~2.5% of triggers)
~83% of runs declared good by the DQM
Tracker operated in peak and deconvolution (default for collisions) modes
S/N in peak mode as in CRAFT08
S/N in deconvolution scales as expected
Tracker readout at high rate (up to 100KHz) without any surprise (both in Peak and Deco mode)
Alignment precision is significantly better than originally anticipated for start up conditions
Impact parameter resolution is essentially equal to the one based on ideal Monte Carlo conditions
CRAFT was very useful to prepare the detector for physics running, but a lot more work is necessary to maximize the tracker potential. FY10 will likely turn out to be the most critical and intense operations period ever confronted.

17. Regina Demina University of Rochester
Conclusions
In 2000 CMS collaboration made a bold decision to build an all-silicon tracking system on an precedential scale – a factor of 10 larger than any existing one
Almost 10 year later it is ready for physics data
FNAL ROC
September 30, 2009
Regina Demina University of Rochester