09 September 2010

Erik Huemer (HEPHY Vienna)

Upgrade of the CMS Tracker for High Luminosity Operation

OEPG Jahrestagung 2010

Upgrade of the CMS Tracker for High Luminosity Operation

2Erik Huemer (HEPHY Vienna)09 September 2010

Outline

• Why and What?• Challenges for the CMS Tracker• Possible Solutions

- Radiation Hard Sensor Materials

- Highly Integrated Sensors

- Intelligent Track-Trigger Modules

• Summary

Upgrade of the CMS Tracker for High Luminosity Operation

sLHC Upgrade: Why and What?

Current LHC design specifications:• Center-of-mass energy ECM = 14 TeV

Momentum per particle: p = 7 TeV/c

• Luminosity L = 1034 cm-2s-1

ECM is limited by:

Luminosity is limited by:

3Erik Huemer (HEPHY Vienna)09 September 2010

L f nN1N2A

p qBR

Upgrade of the CMS Tracker for High Luminosity Operation

Increases number of interactions per time!

• Advantage: – More statistics

• Disadvantages: – Higher particle

background– Higher radiation

level– Higher occupancy

sLHC: A Luminosity Upgrade

4Erik Huemer (HEPHY Vienna)09 September 2010

Upgrade of the CMS Tracker for High Luminosity Operation

• Tracker needs to provide input to the trigger: Track-Trigger on pt

• Increase of radiation level• Higher granularity to resolve dense packing of

tracks

All while reducing the material budget!

Very challenging as:• MB of current tracker exceeds expectations• Now more channels and intelligent modules• Needs more power needs more cooling

Challenges for the Tracker

5Erik Huemer (HEPHY Vienna)09 September 2010

Upgrade of the CMS Tracker for High Luminosity Operation

Radiation Hard Sensor Materials

6Erik Huemer (HEPHY Vienna)09 September 2010

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

• N or P doped silicon• N or P doped strips• Thickness of the substrate

Upgrade of the CMS Tracker for High Luminosity Operation

Highly Integrated Sensors

7Erik Huemer (HEPHY Vienna)09 September 2010

Direct connection between sensor and readout• Now: External pitch-adapter made of glass• Future: Integrated pitch-adapter and

readout-Chip- Less material- Easier to build module- Higher density of readout channels

Upgrade of the CMS Tracker for High Luminosity Operation

Fast measurement of momentum (Pt) for trigger decision

• Pt through measurement of track curvature

• Track curvature through determination of “dislocation” of the track after some mm

• 2 parallel sensors with some mm space• “Stiff” track with little curvature with high

momentum only Strips hit, only little dislocated High Pt

Module needs integrated “intelligence” for pattern-determination over 2 sensors

Intelligent Track-Trigger Modules

8Erik Huemer (HEPHY Vienna)09 September 2010

~200μm

Upper Sensor

Lower Sensor

Pass Fail

~100μm

~1mm

Upgrade of the CMS Tracker for High Luminosity Operation

9Erik Huemer (HEPHY Vienna)

• Actual data was taken• Results are promising

Development analysis framework• Different geometry of sensor• Different read-out logic

• Former analysis concept fails

• Highly object oriented (C++, ROOT)• Quick exchange of single analysis parts

Proof of concept!

Intelligent Track-Trigger Modules

09 September 2010

Upgrade of the CMS Tracker for High Luminosity Operation

10Erik Huemer (HEPHY Vienna)

Summary

09 September 2010

• LHC upgrade crucial for future productivity• Challenges are dealt with

- Radiation hard materials under review

- Integrated sensor prototypes

built, tested, partially analysed

- Intelligent modules for early detection

built , tested, will be analysed

Upgrade of the CMS Tracker for High Luminosity Operation

11Erik Huemer (HEPHY Vienna)09 September 2010