from the atlas sct endcap module production to the commisionning

October 05, 2005 D. Ferrère, RD05 Florence 1

From the ATLAS SCT endcap module production to the

commisionningD. Ferrère, University of Geneva

in behalf of the ATLAS SCT collaboration

Overview:Overview: Introduction of SCT Introduction of SCT The endcap modules and the specificationsThe endcap modules and the specifications The module production and logisticsThe module production and logistics Production results: yield and statisticsProduction results: yield and statistics The endcap macro-assembly: status and resultsThe endcap macro-assembly: status and results The integration and commissioning The integration and commissioning


Atlas ExperimentAtlas Experiment

Barrel Electromagnetic CalorimeterBarrel Electromagnetic Calorimeter

Barrel ToroidBarrel Toroid

Good tracking performances that are required for:

Secondary vertices

Impact parameters resolution

Track isolation

Measurement of high momentum particles

Main physics motivation is the search for the Higgs boson, but not only given the large range of

physics opportunities!


The SCT Semiconductor TrackerThe SCT Semiconductor Tracker

4 barrels

5.6 m

1.04 m

1.53 m

SCT is made of 4088 modules:

• ~ 61 m2 of silicon

• 15,392 silicon wafers

• ~ 6.3 million of readout channels

Endacp A: 9 wheels

Endacp C: 9 wheels

Layout was done such that 4 space points can be reconstructed


Endcap module typesEndcap module types

1976 modules mounted on the 2 endcaps:1976 modules mounted on the 2 endcaps:

936 Outer Forward Modules936 Outer Forward Modules

640 Middle Forward Modules (incl. 80 Short Middle)640 Middle Forward Modules (incl. 80 Short Middle)

400 Inner Forward Modules400 Inner Forward Modules

A module consists of 768 readout strips on each side with a constant angular pitch pointing towards the center of the wheel. Pitch between 70 to 90 m.

Middle short Middle short


Expanded view of an outer moduleExpanded view of an outer module

2 detectors strip-chained and readout at one end by 6 binary chips (ABCD3T) on each side 768 readout strips per side.

Clock, control and signal are transmitted optically.Detectors are mounted back to back with a 20 mrad stereo angle.


Module requirementsModule requirementsElectrical specifications:(Based on a full set of digital/analog chip characterization + bias tests)

• Noise occupancy at 1 fC less than 5x10-4 also related to the input noise• Less than 1 % dead channels ( 15/1536 ) – From the response curve test• Detector current less than 20 A at 350V per detector.• Long Term Test (LTT) operation for 18-24 hours cold:

> thermistor on hottest part of hybrid at ~10 ºC > Chip and detector biases and currents should remain stable

top side

bottom side


Module requirementsModule requirementsMechanical specifications:• XY alignment - 13 parameters defined but critical are

– Front-to-back detector alignment: midYF within ± 5 m– Individual detector angles: a1 to a4 within ± 130 mrad– Mounting hole and slot alignment: mhx, mhy and msy within ± 20 m

• Z detector profile – 50 points are focused on the Si-detectors and per module side. None of them should exceed ± 115 m envelope.

• Chip and fanins must be assembled within a defined envelope to avoid clashes with neighbor modules

• The alignment and the profile must survive 10 thermal cycles between +35 ºC down to –30 ºC

• Ceramic mounting surface should be clear of cracks (very fragile part)

13 XY alignment parameters 50 Z focus points for the module profile


Module production and endcap flow diagram Module production and endcap flow diagram

Module Productionand QA Cluster

Com

plete

Fanin production(CNM Barcelona)

Spine Production(Protvino)

Hybrids(Cicorel + Freiburg)

Others: Washers, glue

EndCap C macro-assembly Liverpool (UK)

EndCap A macro-assembly

Nikhef (NL)

In progress ...

Hybrid QA Site

Spine QA & rework(CERN)

ID InstallationCERN ATLAS pit

May/June 2006

ID IntegrationTests and cosmic run

CERN SR1

January 2006 March 2006

Si-Detectors(Hamamatsu & CiS)

• Cracow INP• Freiburg Univ.• CLRC, RAL

• Freiburg Univ.• Geneva Univ. CERN• Manchester Univ. Liverpool,

Glasgow• MPI, Munich Prague Charles Univ, Prague Czech Tech. Univ.• Melbourne CERN• Nikhef• Valencia


Module assembly resourcesModule assembly resources- 7 assembly sites in total involving 12 institutes or Universities - Up to 6 technicians/site (~3 FTE) for the module assembly - Up to ~8 physicists and PhD per site (~2 FTE) for the module QA

- Component selection and reception tests ~2h- Alignment and assembly of detectors ~2h + 24h glue curing- Detector current check and visual inspection ~40min- Assembly with hybrids and fanins ~1h30 + 24h glue curing- Wire bonding ~3h- Detector current check and visual inspection ~15min- Metrology survey ~30min- Thermal cycling ~18h- Metrology survey ~30min- Electrical characterization ~2h30- Long Term Test electrical characterization ~24h- Inspection and packing for storage ~20min

From start to the end a module fabrication takes ~9 working days/module!

In practice a module is issued after 3 to 4 weeks!


Module assembly procedure Module assembly procedure

Detector alignment

Assembly with spine

Assembly with hybrid and fanins

Wire bonding


Endcap module production Endcap module production Production Started in June 03 and completed in May-June 05

Total : 2377Outer : 1106Middle : 775Inner : 496

Number of modules were made with a 20% contingency to allow up to 15% lost at the production sites and 5% at the macro-assembly sites.

Max production rate:Max production rate:~55 modules/week~55 modules/week

Outer : 94.7%MidL : 94.4%MidS : 88.3%Inner : 87.4%

Average yield : 93.1%

Front side of an outer module


Few illustrations of problems found – Part of the learning curve Few illustrations of problems found – Part of the learning curve

Si surface

Teflon surfaceDetector scratches due to

trapped debris into the teflon surface of the transfer

plate.Module is out of detector

current specs!Detector broken due to

debris that was sticking on the backplane. This

happened when sucking down on the miniature

alignment stage.Module is broken!The spacer mounted on the

spine was glued with an angle and clash during the assembly

was unavoidable but impossible to anticipate.

Module was aborted!


Electrical QA resultsElectrical QA results

Out of specs

Good

Good

Out of specs


Mechanical QA results Mechanical QA results

Good

Pass

midyF specification inside ± 5 microns mhy specification inside ± 20 microns

Good

Some stats on essential XY alignment parameters

Stereo angle specification 20 ± 0.13 mrad. Defined between front and back detector axis.

Good


Mechanical QA results Mechanical QA results

Front and rear detector profile

GoodPass

ZminF

Good


Endcap macro-assemblyEndcap macro-assembly

Disk 5A in Module to Disk stand at NIKHEFDisk 5A in Module to Disk stand at NIKHEF

Liverpool: Endcap C & Nikhef: Endcap A

52 outer and 40 inner modulesFront side

40 middle modulesRear side


Endcap C disk testing results (Liverpool) Endcap C disk testing results (Liverpool)

Outers : 1576e-

Middles: 1529e-

Inners : 1070e-

Short Middles : 907e-

Average Input noise on the complete

endcap C

Endcap A has similar results so far...Endcap A has similar results so far...


Endcap C disk Thermal study (Liverpool)Endcap C disk Thermal study (Liverpool)

Tcoolant= -22 ºC, Tambient= -8 ºC

Average±RMS:Hybrid main point: - 20.8 ± 0.8 ºCDetector-end temp: -18.5 ± 0.6 ºC

Main Point Temperature

-4.0

-2.0

0.0

2.0

4.01

2 3 45

67

89

10

11

12

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14

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16

17

18

1920

2122

23242526

27282930

3132

3334

35

36

37

38

39

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41

42

43

44

4546

4748

4950 51 52

(T. Jones)


Endcap statusEndcap status

Endcap C (Liverpool):• Module to disc completed and tested• Discs 9 to 5 in cylinder• FSI to mount on discs 1 to 4• Service to cylinder started: cooling, LMT, fibers, DCS

Delivery to CERN in January 06

Endcap A (Nikhef):• Module to disc completed from 9 to 5• Disks 9 to 7 in cylinder• Disk 5 under test• Modules to be mounted on disc 4 • Services to discs on disc 1 & 3 to do• Services to cylinder started: cooling, LMT, fibers, DCS

Delivery to CERN in March 06

EC-C cylinder with discs 6 to 9 at LiverpoolEC-C cylinder with discs 6 to 9 at Liverpool

EC-A Disk 8A inserted into cylinder at NikhefEC-A Disk 8A inserted into cylinder at Nikhef


Integration and commissioning at CERN SR1Integration and commissioning at CERN SR1

1. The 2 ECs will arrive at CERN in January 06 and March 062. Reception tests: visual inspection, leak test and electrical

tests3. Final SCT assembly4. Integration with TRT5. Combined tests SCT/TRT - 9 SCT discs will be tested together

on 1 sector 6. Installation into the pit foreseen in May and June 06

Cantilever stand with 1 endcapCantilever stand with 1 endcap TRT trolley in aligned positionTRT trolley in aligned positionfor the integrationfor the integration


ConclusionsConclusions

• SCT is one of the largest Si-Tracker (~61 m2).•A lot of expertise is essential from physicists, engineers and technicians in various fields such as: physics, mechanics, electronics, computing, thermodynamics,...• Even with the strict requirements, a module yield as high as 93.1% was achieved . 2377 modules have been built and 1976 will be used in SCT.• The EC module production was a great success and experience in all the assembly sites: 7 sites involving 12 universities and institutes.• Modules are completely mounted on discs for EC-C and half for EC-A and module performances are as expected!• The macro-assembly, service assembly, integration and commissioning are on the way or about to start at Liverpool, Nikhef and at CERN.• The installation into the pit is close: May 06 and June06.


Extra slides


23 overlapping interactions every bunch crossing (at the full Luminosity)

A bunch-bunch crossing every 25ns (40MHz)

Maximum equivalent 1 MeV neutron fluence after 10 years is ~ 2.1014 n/cm2

Operating temperature on silicon detectors is -7oC to contain the reverse annealing and the leakage current

BUT the maintenance will likely require yearly warm-up of 2 days at 20oC and 2 weeks at 17oC

Operation in a 2 Tesla solenoid field

Material < 0.4 X0 at the outer SCT envelope

SCT coverage up to =2.5

More than 99% hit efficiency is required

Running conditions and featuresRunning conditions and features


Module componentsModule componentsHybrid: - 6 copper-kapton layers laminated onto a carbon-carbon substrate- Equipped with 12 ABCT3T readout chips and opto-chips for clock/control and readout

Detectors:- 5 detector types made in 4 inch wafers by 2 manufacturer (Hamamatsu and CiS)- 770 strips (1st and last not readout) of 20 micron width with an average pitch of ~80 m

Fanins:- Aluminum strips on glass used for electrical connection and thermal isolation

between hybrid and detectors. Different sets for the 3 module types.- 4 items per module: 2 left and 2 rightsSpine:- Made of TPG (Thermal Pyrolytic Graphite) for the excellent thermal conductivity

and AlN ceramic pieces for the mechanical stiffness. All in one single item during the module assembly.

Location pads:- very precise hole and slot made on an Aluminium washer and glue onto FR4

piece. The slot washer is glued on the spine and the hole is overlapping the hybrid and the spine.


SCT production Database Oracle DB (kernel 9i)

Why?• Traceability of the items, shipped items, assemblies and tests that had been made• Most of the relevant test data and parameters were stored in structured way otherwise stored in raw data• Useful GUI has been made either for upload or report thanks to:

– Java applications for massive data upload– Web interfaces (SQL form) for individual data access or report– Java or other applications coupled with root display for statistics and reports

• Encourages auto-discipline. Data transparent to all the collaboration and DB entries were one of the requirements to be qualified for the module production.


0.00001

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0 2 4 6 8 10 12 14 16 18 20Time (h)

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Icc (mA)

Idd (mA)

Idet (microA)

Noise Occupancy

Electrical QA results Electrical QA results

Long Term Test (LTT)After some stats decreased from 24h to 18h duration

Very rare problems found with the modules (0.05%)!In principles problems are detected earlier during hybrid LTT.


Endcap macro-assemblyEndcap macro-assembly

from the atlas sct endcap module production to the commisionning

Documents

rd05 florencemodule

detector alignment

endcap modules

detector biases

rd05 florenceexpanded

neighbor modules

c chip

mz detector profile