Upgrade of the CMS Tracker for High Luminosity Operation

1. Upgrade of the CMS Tracker for High Luminosity Operation Erik Huemer (HEPHY Vienna) OEPG Jahrestagung 2010

2. Outline • LHC Upgrade to explore Physics Potential • Challenges for the CMS Tracker • Required Advances in Technology R&D lines followed by HEPHY • Radiation Tolerant Sensors • Highly Integrated Sensors • pt Track-Trigger Modules • Summary Erik Huemer (HEPHY Vienna)

3. LHC Upgrade toexplorePhysics Potential • Operation until 2020 • Design luminosity: L = 1034 cm-2 s-1 • Continuephysicsprogramm • Increase in luminosity • ADVANTAGE: morestatistics • Also disadvantages 2020 2014 2016 2012 2018 2010 Erik Huemer (HEPHY Vienna)

4. LHC Upgrade toexplorePhysics Potential • The CMS tracker Erik Huemer (HEPHY Vienna)

5. LHC Upgrade toexplorePhysics Potential • Track densities at different interaction rates • Disadvantages: • Higher particle background • Higher radiation level • Higher track density 1032 1033 1035 1034 Erik Huemer (HEPHY Vienna)

6. Challenges for the Tracker • Increase of radiation level • Higher granularity to resolve dense packing of tracks • Tracker needs to provide input to the trigger: • Track-Trigger on pt to enable selection of interesting events • Amount of material in the tracker has to be minimized: • Interactions in the primary vertex • NOT with tracker material Erik Huemer (HEPHY Vienna)

7. Three R&D Lines • R&D linesfollowedby HEPHY • Radiation Tolerant Sensors • HighlyIntergrated Sensors • pT Track-Trigger Modules Erik Huemer (HEPHY Vienna)

8. 1. Radiation Tolerant Sensors • Important operating parameters which change with irradiation • Full Depletion Voltage (VFD) • Reverse Bias Current (Dark Current) • Charge Collection Efficiency (CCE) • Silicon bulk materials and manufacturing processes • Float Zone (FZ) or Czochralski (CZ/MCZ) silicon • MCZ n-n sensors • FZ n-n sensors • MCZ n-p sensors • FZ n-p sensors • Thicknessofthesubstrate Erik Huemer (HEPHY Vienna)

9. 2. Highly Integrated Sensors • Now: External pitch-adapter and readout-chips • Future: Integrated pitch-adapter and on-sensor readout-chip • Reduces material • Higher flexibility • Handles granularity Erik Huemer (HEPHY Vienna)

10. 3. pt Track-Trigger Modules Pass Fail • Fast measurement of momentum (Pt) for trigger decision • Pt through measurement of track curvature • Track curvature through determination of contact angle on the tracker • 2 parallel sensors with some mm space • “Stiff” track with little curvature with high momentum only • Strips hit, only little dislocated • High Pt Upper Sensor ~1mm ~200μm Lower Sensor ~100μm Upper Sensor Lower Sensor Erik Huemer (HEPHY Vienna)

11. pt Track-Trigger Modules • Prototype @ CERN • Tested at various angles • Collected 1 TB of data • Development analysis framework • Different geometry • Different read-out logic • Former analysis concepts do not work • Highly object oriented (C++, ROOT) • Quick exchange of single analysis parts Erik Huemer (HEPHY Vienna)

12. Summary • LHC upgrade crucial for future productivity • CMS tracker has to be rebuilt • Three R&D lines • Radiation hard materials under review • Highly integrated sensors • built, tested, partially analysed • pT track-trigger modules • built , tested, will be analysed with new software Erik Huemer (HEPHY Vienna)

13. Erik Huemer (HEPHY Vienna)

14. Backup Slides Erik Huemer (HEPHY Vienna)

15. Luminosity Numberofbunches Amountofparticles in a bunch Frequencyofbunches Size ofinteractionarea Erik Huemer (HEPHY Vienna)