DETECTOR UPGRADES FOR THE HL-LHC

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D ETECTOR U PGRADES FOR THE HL-LHC

XIII CPAN days, March 2022, Huelva

Carlos Lacasta, IFIC-Valencia

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The HL-LHC

Detector Upgrades for the HL-LHC

Right after the LHC commisioning in 2010, CERN approved the path to an upgrade of the accelerator complex that would provide a higher “useful luminosity” to the detectors.

The main challenges

Beam current and brightness

(number of protons in beam) New/better injectors

LIU (LHC Injector Upgrade)

Interaction point

Useful luminosity.

Reduce radiation damage on IP and keep pile-up under control.

For efficiency it is better to have a constant luminosity for a longer time.

Luminosity leveling.

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The HL-LHC

Major interventions on more than 1.2 km of the LHC tunnel

New IR-quads Nb3Sn (inner triplets), New 11T Nb3Sn (short) dipoles, Collimation upgrade, Cryogenics upgrade, Crab Cavities, Cold powering, Machine protection…

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The LHC/HL-LHC plan

Today

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LHC Run 3

Prepare for high intensity and ultimate luminosity.

ATLAS/CMS

Levelled @~2.0×10

³⁴

cm

^-2

s

^-1

high pile up ~60

LHCb

Levelled @ 2.0x10

³³

cm

^-2

s

^-1

Technical limits for

machine and detectors

ALICE and LHCb upgraded

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The LHC/HL-LHC plan

Today Long shutdown

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The HL-LHC

A luminosity levelled @ 5×10³⁴ cm^-2s^-1 , an integrated luminosity of 250 fb^-1/year that will yield the expected 3000 fb^-1 12 years after the upgrade.

Very high pile up: ~140

ATLAS and CMS upgraded

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The LS3 schedule

Despite the great progress in the HL-LHC project and the upgrades of ATLAS and CMS, delays have accumulated due to COVID-19 and technical challenges.

CERN very recently (Jan. 2022) decided to extend Run 3 by 1 year and LS3 by 6 months.

No further extensions of Run3 nor LS3 are possible, for technical and political reasons.

Current HL-LHC end date (2038) implies only 2500 fb^-1 will be provided to ATLAS and CMS.

The goal of providing 3000 fb^-1will not happen before 2041.

Final decision on the HL-LHC long term schedule

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The upgrade of the detectors

Alice and LHCb do not use the full luminosity provided by the machine.

ATLAS and CMS greedily consume it.

GOAL: keep similar performance in harsher environment than in the current detector

Increased Radiation levels and detector occupancy (higher granularity)

Tracking performance is critical.

Maintaining (even improve) physics sensitivity is very challenging for the trigger

LHCb Alice CMS ATLAS

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The ALICE Upgrade

The Heavy Ion program.

High precision measurements of rare probes at low p_T, which cannot be selected with a trigger.

Target a recorded Pb-Pb luminosity ≥ 10 nb^-1 to gain a factor 100 in statistics over the Run1+Run2 programme.

Read out all Pb-Pb interactions at a max. rate of 50 kHz Perform online data reduction based on reconstruction of clusters and tracks

Improve vertexing and tracking at low p_T

• New Inner Tracking System (ITS)

• New readout chambers for TPC

• New muon forward.

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The ALICE Upgrade

Detector Upgrades for the HL-LHC New ITS and the MFT use the

same CMOS pixel sensor, ALPIDE

GEM based TPC readout

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The ALICE Upgrade – Low mass detectors

The new ALICE Inner Tracker (ITS2) has given a big push in the reduction of material:

• Inner layer: 0.35 %X0

• Outer layer: 0.8 %X0

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Jul-Aug ‘20 Reinstall T

ALICE C

PC in avern

Reinstall Miniframe

Aug-Sep ‘20 Install cage and central beampipe

Install MFT and FIT-C

Install ITS2 LS2 end

July ‘21 March ‘22

Feb-June ‘21 Dec-Jan ’21

Oct-Nov ‘20

Install FIT-A

Install ITS2

Standalone commissioning Global Commissioning

project finished O2 compute farm

The ALICE Upgrade

Project finished and very promising results from Pilot Run

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The ALICE Upgrade beyond Run4

ALICE - ITS3

bent, wafer-scale CMOS detector

replace inner 3 layers of ITS2 with ITS3

280 mm long sensor ASICs

out of 300 mm long stitched wafers 20-40 µm (0.02-0.04% X0)

bent shape with radius 18/24/30 mm

Air cooling

Carbon foam ribs to hold the sensor Interconnection tests Mechanical mock-up

First results on beam tests look

encouraging.

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The LHCb Upgrade

Beyond Flavour: general purpose detector in the forward region.

Precision studies: Need to go to very high statistical precision.

Remove limitations from Hardware trigger.

Upgrade essential.

b s

Full Software Trigger

➔ Transform entire detector to 40MHz readout

↳ Remove 1 MHz bottleneck

➔ Improve efficiency in hadronic modes

Reach ^𝔏=2x10³³ cm^-2s^-1

➔ Re-design of several subdetectors

➔ Overhaul of readout

Challenges:

➔ Maintain Physics performance with high occupancy and pile up

↳ Granularity, readout speed and trigger

➔ Radiation hardness

➔ Control sytematics con match statistics: low material budget

Pre-phase I LHCb trigger yield

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The LHCb Upgrade

Full So

ftware Trigger: replac

e r/o an

d DAQ.

40 Tb/s of data to trigger farm.

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The LHCb Upgrade

Vertex Locator (VELO):

Replace with full Si-pixel

New Upstream Tracker (Si-strip)

RICH

OT and IT: replaced by SciFi Tracker

Muon System Calorimeters:

Replace FE electronics Remove PS/SPD

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The LHCb VELO Upgrade

From Strips to Pixel (55x55 µm²) based vertex detector.

Closer to beam

Radiation resistance (8x10¹⁵ 1 MeV n_eq cm^-2)

Minimise material: micro channel evaporative CO₂ cooling Readout at 40 MHz with VeloPix (an evolution of TimePix3).

Should withstand ~400 Mrad

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The LHCb VELO Upgrade

Side A installed.

Side C at CERN in April

Installed hopefully before physics beams.

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The LHCb - SciFi

Replace completely straw tube and inner Si strips.

Scintillating Fibres (SciFi). Fast track reconstruction in trigger

• 6 layers of 2.5m long fibres with 250 µm diameter.

• SiPM readout

• Neutron damage to SiPM: cooled to -40^oC

10 Gb/s per SiPM

PACIFIC chip

64 channels (2 per SiPM) Dual 25ns integrators 10ns shaping

3 comparators per channel

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The LHCb - SciFi

Transportation of the entire SciFi to the LHCb

cavern completed on February 16th 2022 C-Frames around the beam pipe

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The LHCb – Calorimeter Upgrade

Preshower (PS) and SPD removed (mainly HW trigger) ECAL and HCAL detectors will be kept.

PMT gain reduced by a factor 5 to reduce aging Trigger-less readout @ 40MHz

New Electronics ICECAL ASIC

F E B

ICECAL chip

ADCs FPGA

PMTs

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The LHCb – Calorimeter Upgrade

New electronics already

installed and in commisioning phase.

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The LHCb Upgrade II

CERN-LHCC-2017-003 LHCb-PUB-2018-009

2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037

Run 2

L = 4 x 10³² Lint~ 8 fb^-1

LS2 Run 3

Lumi 2 x 10³³ LS3 LS4 Run 5,6

Lumi 1-2 x 10³⁴

Run 4

Lumi 2 x 10³³

L_int = 50 fb⁻¹ Lint= 300 fb⁻¹

Expression of Interest and Physics case in place.

Framework TDR just released

Support from the 2020 update of the European strategy.

Increase Luminosity by a factor 7.5

CERN/LHCC 2021-012

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The LHCb Upgrade II

VELO4D tracking Timepix4-like iLGAD, 3D sensors

New ECAL, no HCAL New MUON system TORCH

Time of Flight (ps)

PID below RICH threshold

RICH

Improved PID Use timing (ps)

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ATLAS and CMS

Maintain (improve) today’s performance at 5-10 times higher pile-up and luminosity.

Survive ~10 years of extreme radiation

Many systems need upgrading, but most importantly the Tracker.

Current trackers will not withstand radiation beyond 500 fb^-1.

Finer granularity (space/time) is needed for the pattern recognition at pile up of 140.

Not enough bandwidth to readout the high volume of data.

CMS ATLAS

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ATLAS and CMS

Trigger: HW 1 MHz, 5.2 Tb/s, 10µs latency SW: 10 kHz, ~52 Gb/s

Trigger: HW 750 MHz, 12.5µs latency SW: 7.5 kHz ~60 Gb/s

New tracker.

New timing detectors Enhance Muon detectors

CMS, in addition, replaces the forward calorimeter

2 level trigger

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ATLAS and CMS - Muons

Existing detectors are expected to cope with HL-LHC radiation and luminosity.

They will be extended in the weakest parts.

Much of the electronics, however, will be replaced to improve the trigger.

ATLAS

New Small Wheels.

Improve tracking and trigger

CMS

Forward 1.6<|η|<2.4

• L1 rate reduction to enhance redundancy

• GEMs: GE1and GE2

• iRPC: RE3and RE4

Very forward extension

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ATLAS New Small wheels (Phase I)

New

New Muon Small Wheels (More Granularity Muon Small Wheels (More Granularity))

• Plan to replace muon small wheels with improved trigger capability:

need <1mrad angular resolution and associated trigger vector capability

• Status:

•Converging on the choice of the technology for precision tracking and trigger

tracking and trigger

•MicroMegas for precision coordinates and TGC for trigger are the main candidates

•Vigorous milestone plan for 2012 to demonstrate feasibilityVigorous milestone plan for 2012 to demonstrate feasibility

•TDR to be ready for early 2013

•Project being set up for ATLAS internal approval in 2012

Trigger rate reduction studied using

data data

(20GeV p

~ 1/6

in 1.3< <2.5

(20GeV p_T threshold)

11

Select&tracks&pointing& to&

the&IP&matching&the&big&

wheels

First large system based on MicroMegas.

Reduce fake rates and keep precision at high rates.

Combination of

• MicroMegas (1200 m²) for precision, and

• small strip Thin Gap Chambers (1200 m²) for trigger and bunch id.

Lowering of second NSW, Nov 4th 2021.

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CMS Muons – GEM1 station (Phase I)

Already installed and DAQ integrated.

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CMS – Muon upgrade for Run 3

All Muon demonstrators at high eta region installed

One slice of endcap equipped with new chambers.

Commissioning is ongoing.

Drift Tubes DT Slice test:

Phase II on-Board electronics installed

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CMS – Muon DT electronics for Phase II

Muon Drift Tubes

Current muon detectors expected to widstand HL-LHC radiation levels.

Improved z/t resolution

Electronics upgraded to cope with 40 MHz readout

(digitization on-board, including TDC) and sent un-filtered to backend electronics.

Trigger backend running sophisticated algorithms for maximum resolution.

Trigger rates of 750 kHz.

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ATLAS Calorimeters

Replacement of FE and BE electronics to digitize and move off- detector data at 40 MHz.

EM and Hadronic calorimeter don't require upgrade. 10% of Hadronic calorimeter PMTs will be replaced.

Hadronic Calorimeter mechanics modified to allow for eaiser access and mantainability.

TilePPr (PreProcessor)

Off-detector, takes data from detector boards and send to trigger and DAQ

Mechanical links

TiIlePPr (2020): ATCA8U ~ 35 x 28 cm

Throughput (16 Gb/s line): RX: 2 Tb/s Gb/s ; TX: 1 Tb/s 32 Firefly , 10 FPGA

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CMS calorimeters - HGCal

High density Low density

Endcap Calorimeters need to be replaced due to radiation induced loss of transparency.

Replace with HGCal (High Granularity Calorimeter) 5D calorimetry.

600 m² of Si and 400 m² of scintillator: 6 M r/o channels.

Si Sensor order after summer (8” line quality very good) Hadron part: SiPM-on-Tile configuration almost finalized ASICs: on prototyping stage

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Timing Detectors

ATLAS and CMS plan to install new layers providing precise track timing information of the order of 30-50 ps.

BTL: Barrel time layer LYSO crystal bars + SiPM on each end.

ETL: Endcap time layer.

Silicon LGAD (Low Gain Avalanche Detectors)

16x16 (1.3x1.3 mm²) pixel sensor, bump bonded to ETROC readout ASIC.

2 layer disk

(~2 hits per track)

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Timing Detectors

ATLAS and CMS plan to install new layers providing precise track timing information of the order of 30-50 ps.

HGTD: High Granularity Timing Detector.

ATLAS implements only in the Endcap region.

4 layers each with 35-70 ps.

At least 2 hits per track.

Silicon LGAD Sensors

15x15 (1.3x1.3 mm2) pixels 50 µm thick

Bump bonded to the ALTIROC readout ASIC

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ATLAS and CMS Trackers

OT

IT

5 layers of pixels

Light(1/2 current weight))

• Design, new materials

• new cooling (CO2)

Granularity(x5 higher) to keep low occupancy.

- pixels: ~ 50x50 with first layer replaceable.

- Strips: short (2.5-5 cm) 75-90 µm pitch

Radiation tolerance

n-in-p planar and 3D sensors,

up to NIEL ≃2 x 10¹⁶1 MeV n_eq/cm²and TID of 1 GRad

Extend η coverage to 4

Surface (m2) # Channels # Modules

Pixel 13 5.1 G 9.2 k

Strip 165 60 M 18 k

Surface (m2) # Channels # Modules

Pixel 4.9 2 G 4 k

Macro. Pix 25 170 M 5.6 k

Strip 190 43 M 7.6 k

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ATLAS & CMS pixel detectors

Common development of r/o ASIC (RD53):

they have a “customized” version for each detector

3D pixel sensors to cope with high radiation levels. Planar at higher radius

Smaller pixels for higher occupancy: connectivity to electronics (hibridization).

Replaceable inner layers to cope with very high radiation levels.

Sensor market survey being finished.

CMS: two types of modules

CMS ATLAS

ATLAS have >3 types of modules

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CMS Tracker

New concept:

p_T filtering in stacked double layersof silicon wafers

coincidence hits read out at 40MHz and combined off-detector to form track trigger primitives

Only 2 types of modules

In production mode.

30 % of sensors received

2S: 2 strip sensors 10x10 cm

2x1016 strips 5 cm long 90 µm pitch

PS: pixel-strip sensors Pixel:

Size : 5 x 10 cm2 Pitch : 100 µm Length : 1.5 mm No. of strips : 32x960 Strip:

Size: 5 x 10 cm2 Pitch: 100 µm Length: 2.5 cm No. of strips: 2x960

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ATLAS Tracker

Production Endcap Wheels

Modules on double sided CF local support structures (staves and petals).

Local support structures on global mechanical structures.

Endcap Structure

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ATLAS Tracker

Sensor production started.

Readout ASIC production started.

Sites getting ready for assembly.

2 barrel modules, 9 endcap modules

Barrel Staves

Endcap Petals

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Computing

Two decades contributing to LHC distributed computing infrastructure (Worldwide LHC Computing Grid, WLCG) and R&D at the highest level.

ü ~5% of WLCG resources (20k CPU-cores, 15 PB disk, 20 PB tape),

~1500M CPU hours delivered since 2004

ü Providing 1 of the 13 Tier-1 sites worldwide (PIC)

ü Federated Tier-2 sites for ATLAS (IFIC, IFAE, UAM), CMS (CIEMAT, IFCA), LHCb (USC, UB)

ü Among the most reliable sites in WLCG

WLCG-ES : A story of success

«There is a gap between affordable and needed resources in computing».

This is certainly so for the HL-LHC challenges that require person-power for the needed R&D.

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Computing

Two decades contributing to LHC distributed computing infrastructure (Worldwide LHC Computing Grid, WLCG) and R&D at the highest level.

ü ~5% of WLCG resources (20k CPU-cores, 15 PB disk, 20 PB tape),

~1500M CPU hours delivered since 2004

ü Providing 1 of the 13 Tier-1 sites worldwide (PIC)

ü Federated Tier-2 sites for ATLAS (IFIC, IFAE, UAM), CMS (CIEMAT, IFCA), LHCb (USC, UB)

ü Among the most reliable sites in WLCG

WLCG-ES : A story of success

«There is a gap between affordable and needed resources in computing».

This is certainly so for the HL-LHC challenges that require person-power for the needed R&D.

However, Run 3 is round the corner, and should not be forgotten.

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To finish

ü Run 3 round the corner

➔

ALICE and LHCb with an upgraded detector

➔

ATLAS and CMS with some “tweaks” in their detectors and trigger systems.

➔

The four experiments eagerly waiting for the new data to come

ü ATLAS and CMS getting ready for production of the upgraded detectors

↳

End of prototyping/Pre-production

↳

Procurement of parts starting

↳

Sites getting ready for the assembly.

ü Is there life beyond LS3 ?

➔

LHCb and ALICE planning for “life” after Run 4.

➔

ATLAS and CMS will certainly plan for replacement of inner pixel layers