Geometry baseline of the new Inner Tracking System, ALICE Chinorat Kobdaj

Geometry baseline of the new Inner

Tracking System, ALICE

Chinorat KobdajSuranaree University of

Technology, ThailandOn behalf of the ALICE

CollaborationAug 8, 2013

APCTP 2013 LHC Physics Workshop @ Korea, August 6-8, 2013, Konkuk Univeristy, Seoul, South Korea

The ALICE Detector

The Current ALICE Detector2

APCTP 2013 LHC Physics Workshop @ Korea, August 6-8, 2013, Konkuk Univeristy, Seoul, South Korea

Introduction to the Inner Tracking System upgrade

ALICE ITS (present detector)

ALICE ITS

Current ITS 6 concentric barrels, 3 different technologies• 2 layers of silicon pixel (SPD)• 2 layers of silicon drift (SDD)• 2 layers of silicon strips (SSD)

The Current ALICE Inner Tracking System

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ALICE ITS

ALICE ITS

APCTP 2013 LHC Physics Workshop @ Korea, August 6-8, 2013, Konkuk Univeristy, Seoul, South Korea

LoI and ITS CDR endorsed by LHCC in Sep 2012

APCTP 2013 LHC Physics Workshop @ Korea, August 6-8, 2013, Konkuk Univeristy, Seoul, South Korea 4

2013 Selection of Technology

2014 Final Design

2015-2016 Construction / Test detector modules

ALICE ITS Upgrade

2017-2018 Assembly / Installation

2019-2020 Test run / Full run

2021 Comple

te

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LongShutdown

1

EvaluationTechnology

Construction and Installation

Time Line

R &D

2012 2013 2014 2015 2016 2017 2018

Today

2019 2020 2021 2022

ConceptualDesign Report

Prototype

TechnicalDesign Report

FinalDesign

andValidation

Pb-Pbat

√sNN= 5.1 TeV

Pb-Pbat

√sNN = 5.5 TeV

LongShutdown

2Production/Construction

and Test of Detector

modulesPre-commissioning

and Assembly

LongShutdown

3Complete

Ar-Arhigh

luminosity run

p-Pbat

full energy

Run

Pb-Pb

Selectionof

Technologies Installation in the cavern

Full deployment of

DAQ/HLT

APCTP 2013 LHC Physics Workshop @ Korea, August 6-8, 2013, Konkuk Univeristy, Seoul, South Korea

New ITS Design goals

1. Improve impact parameter resolution by a factor of ~3• Get closer to IP (position of first

layer): 39mm 22mm • Reduce material budget: X/X0

/layer: ~1.14% ~ 0.3% (for inner layers)• Reduce pixel size

ocurrently 50mm x 425mmmonolithic pixels O(20mm x 20mm), hybrid pixels state-of-the-art O(50mm x 50mm)

7APCTP 2013 LHC Physics Workshop @ Korea, August 6-8, 2013, Konkuk Univeristy, Seoul, South Korea

APCTP 2013 LHC Physics Workshop @ Korea, August 6-8, 2013, Konkuk Univeristy, Seoul, South Korea 8

2. Improve tracking efficiency and pT resolution at low pT

• Increase granularity: 6 layers 7 layers , reduce pixel size

• Increase radial extension: 39-430 mm 22– 430 (500) mm

3. Fast readout• readout of Pb-Pb interactions

at > 50 kHz and pp interactions at ~ several MHz

4. Fast insertion/removal for yearly maintenance• possibility to replace non

functioning detector modules during yearly shutdown

Upgrade optionsTwo design options have being studied A.7 layers of pixel

detectors (baseline)B.3 inner layers of pixel

detectors and 4 outer layers of strip detectors

7 layers of pixels

Option A

3 layers of pixels

4 layers of strips

Option B

Pixels: O(20x20µm2 – 50 x 50µm2) Pixels: O( 20x20µm2

– 50 x 50µm2)Strips: 95 µm x 2 cm, double sided 9

APCTP 2013 LHC Physics Workshop @ Korea, August 6-8, 2013, Konkuk Univeristy, Seoul, South Korea

New ITS (baseline)Inner Barrel: 3 layersOuter Barrel: 4 layersDetector module (Stave) consists of - Carbon fiber mechanical support- Cooling unit- Polyimide printed circuit board- Silicon chips (CMOS sensors)

10APCTP 2013 LHC Physics Workshop @ Korea, August 6-8, 2013, Konkuk Univeristy, Seoul, South Korea

Inner Barrel Layers • 3 innermost layers at

r= 22, 28 and 36 mm• Same z-length: 27 cm• Assumed chip size: 15

mm x 30 mm >> 9 chips/module

• X/X0≤ 0.3%Modules Chips

Layer 1 12 108Layer 2 16 144Layer 3 20 180Total 48 432

APCTP 2013 LHC Physics Workshop @ Korea, August 6-8, 2013, Konkuk Univeristy, Seoul, South Korea

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Middle and Outer Barrel Layers• 4 outermost layers at

r= 48, 52, 96 and 102 mm• 84 cm < z-length <

150 cm• Double chip rows per

module• X/X0≤ 0.8%

Modules

Chips

Layer 4

48 2688

Layer 5

52 2912

Layer 6

96 9600

Layer 7

102 10200

Total 298 25400

APCTP 2013 LHC Physics Workshop @ Korea, August 6-8, 2013, Konkuk Univeristy, Seoul, South Korea 1

2

Project Coordination(PL, DPL, SPL, TC, RC,

Upgrade Tasks Coordinators)

Institute Board

(PL, DPL, SPL, TC, Team Leaders)

3. Pixel chip design4. Sensor Post Processing and Mass test

5. Characterization and Qualification6. Inner Layers Module7. Middle Layers Module8. Outer Layers Module

10.Readout Electronics

2. Detector Simulation and Reconstruction1. Physics Performance

PROJECT ORGANIZATION

ITS Operation(RC, PL, DPL, SPL, TC, QAC, CC,

experts)9. Mechanics and Cooling

UPG

RAD

E

APCTP 2013 LHC Physics Workshop @ Korea, August 6-8, 2013, Konkuk Univeristy, Seoul, South Korea 13

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OrganizationParticipating Institutes• CERN• China (Wuhan)• Czech Republic

(Prague)• France IN2P3-

CNRS (Strasbourg)• Italy INFN (Bari,

Bologna, Cagliari, Catania, Frascati, Legnaro, Padova, Roma, Torino, Trieste)

• Korea (Inha, Pusan, Yonsei)

• Netherlands (Nikhef and Utrecht)

APCTP 2013 LHC Physics Workshop @ Korea, August 6-8, 2013, Konkuk Univeristy, Seoul, South Korea

• Pakistan (COMSATS)• Russia (St.

Petersburg)• Slovakia (Kosice

IEP)• Thailand (Nakhon

Ratchasima SUT)• UK STFC

(Daresbury, RAL), Univ. of Birmingham

• Ukraine (Kharkov, Kiev)

• USA (Berkeley)

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Upgraded beampipe - studies

C- side Al section

A-side Al section

Central Be part

APCTP 2013 LHC Physics Workshop @ Korea, August 6-8, 2013, Konkuk Univeristy, Seoul, South Korea

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The upgraded beampipe, drawing v4.0

APCTP 2013 LHC Physics Workshop @ Korea, August 6-8, 2013, Konkuk Univeristy, Seoul, South Korea

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Effect of Al-extension on A sideBackground visible in Central Barrel detectors

a) Entries in (x,y) plane

b) Entries vs Radius

Extract only the secondary vertices physics events to see only the contribution from the new beampipe

PIPE

New ITS

PhysicsBackground

APCTP 2013 LHC Physics Workshop @ Korea, August 6-8, 2013, Konkuk Univeristy, Seoul, South Korea

MC with the beampipe

MC without the beampipe

A-side Al section

C- side Al section

APCTP 2013 LHC Physics Workshop @ Korea, August 6-8, 2013, Konkuk Univeristy, Seoul, South Korea

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Secondary vertices versus z direction

Effect of Al-extension on A sideBackground visible in Central Barrel detectors

MC settings: HiJing central PbPb, interaction diamond: 6 cmSecondary particles further out (>20cm) are clearly negligible ...

Effect ofAl-part

(|z|>40cm)is negligible

< 1 per eventAPCTP 2013 LHC Physics Workshop @ Korea, August 6-8,

2013, Konkuk Univeristy, Seoul, South Korea

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Studies: Impact of materials in forward direction

Compares number of gamma conversion between Al and Be extension on the A-side

APCTP 2013 LHC Physics Workshop @ Korea, August 6-8, 2013, Konkuk Univeristy, Seoul, South Korea

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Results of the beampipe studies

● No impact of Al-extension in terms of background in the Central Detectors

● 80 cm is sufficient for the central part (Be) of the new beam-pipe (no significant background is observed from the Al part further away).

● Forward direction, difference between Al/Be clearly visible, up to 60% of gammas converted at eta~5.5

● Impact of Al-extension on the physics case to be answered by the Forward-Calorimeter teamAPCTP 2013 LHC Physics Workshop @ Korea, August 6-8,

2013, Konkuk Univeristy, Seoul, South Korea

Model 0 in the CDRwith cooling pipes at the

vertices

APCTP 2013 LHC Physics Workshop @ Korea, August 6-8, 2013, Konkuk Univeristy, Seoul, South Korea

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Stave modeling and material budgets

Model 0 in Aliroot of the 1st layer

a = 23 degreeAPCTP 2013 LHC Physics Workshop @ Korea, August 6-8,

2013, Konkuk Univeristy, Seoul, South Korea23

Model 0 material budgetcooling pipe outer radius of 1.5 mm

Model 1 in the CDRwith polyimide microchannel

cooling

APCTP 2013 LHC Physics Workshop @ Korea, August 6-8, 2013, Konkuk Univeristy, Seoul, South Korea

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Model 1 in Aliroot of the 1st layer

a = 57 degreeAPCTP 2013 LHC Physics Workshop @ Korea, August 6-8,

2013, Konkuk Univeristy, Seoul, South Korea25

Model 1 material budget

Model 2 in the CDR with pipe cooling in the

middle

APCTP 2013 LHC Physics Workshop @ Korea, August 6-8, 2013, Konkuk Univeristy, Seoul, South Korea

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Model 2.1 in AliRoot of the 1st layer

a = 57 degree

APCTP 2013 LHC Physics Workshop @ Korea, August 6-8, 2013, Konkuk Univeristy, Seoul, South Korea

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Model 2.1 Material budget with Cooling pipe outer radius =1.5 mm

Model 2.2 in Aliroot of the 1st layer

a = 57 degree

APCTP 2013 LHC Physics Workshop @ Korea, August 6-8, 2013, Konkuk Univeristy, Seoul, South Korea

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Model 2.2 Material budget with cooling pipe outer radius =1.0 mm

APCTP 2013 LHC Physics Workshop @ Korea, August 6-8, 2013, Konkuk Univeristy, Seoul, South Korea 29

Model 3 in the CDR with silicon microchannel cooling

Model 3 in Aliroot

APCTP 2013 LHC Physics Workshop @ Korea, August 6-8, 2013, Konkuk Univeristy, Seoul, South Korea

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Model 3 Material budget

Material Budgets of different models

  CDR(no

overlaps)

Aliroot with overlaps

Model 0

 0.26%  0.324%

Model 1

 0.30%  0.357%

Model 2.12.2

 0.31%

-

 0.378%0.282%

Model 3

- 0.257% 31APCTP 2013 LHC Physics Workshop @ Korea, August 6-8, 2013, Konkuk Univeristy, Seoul, South Korea

The Flip-chip Mounting

Consider the interconnection between ASIC and the module PCB

APCTP 2013 LHC Physics Workshop @ Korea, August 6-8, 2013, Konkuk Univeristy, Seoul, South Korea

CHIP 1

CHIP 2

CHIP 3

CHIP 4CHIP 5

CHIP 6

CHIP 7

CHIP 8

CHIP 9

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APCTP 2013 LHC Physics Workshop @ Korea, August 6-8, 2013, Konkuk Univeristy, Seoul, South Korea

Mounting to the stave

PCB design – inner layer modulesContact pads distributed

over chip surface:

Aliroot Model in TGeo

CHIP 1CHIP 2

CHIP 3CHIP 4

CHIP 5CHIP 6

CHIP 7CHIP 8CHIP 9

34APCTP 2013 LHC Physics Workshop @ Korea, August 6-8, 2013, Konkuk Univeristy, Seoul, South Korea

Results of the flip-chip mounting • Radius of solder balls does not affect the total material budget much (0.002%) • The thickness of the flex cable contributes significantly to the total material budget

Our studies confirm the material budget for inner layers : X/X0 /layer ~ 0.3%

Conclusion

35APCTP 2013 LHC Physics Workshop @ Korea, August 6-8, 2013, Konkuk Univeristy, Seoul, South Korea