EN Seminar The Challenges for Survey and Alignment in CERN Experiments 13 November 2014 Jean-Christophe Gayde EN/MEF-SU

Contents SU section and Experiment Metrology Unit Experiment configuration and survey The geodetic networks A precise geometry at all stages Working in the Experiment environment … Integrated Alignment and Monitoring Systems The future Conclusion

SU section and Experiment Metrology Unit

The SU Section SU Section mandate : EN/MEF-SU Dominique MISSIAEN Deputy: Hélène MAINAUD-DURAND Accelerator & Computing (AC) Experiment Metrology (EM) Jean-Christophe GAYDE Micro Technology & Instrumentation (MTI) Hélène MAINAUD-DURAND SU Section mandate : Definition and maintenance of reference frame Geodetic aspects Dimensional metrology of accelerator and of experiments Positioning and alignment on beam lines Quality controls (infrastructure, installations, components) The R&D related to these tasks

SU-EM unit Provides: The geometrical infrastructure for the detector installation The detector metrology The assembly geometrical follow-up The alignment on the beam lines The as-built measurements R&D as for monitoring systems Knowing that: Detector size varies from some cm to tens of meters From very light structures (composite) to quite heavy ones (1000 of tons) Often unique and complex objects made of many pieces Experiment Collaboration -> Detectors usually not fully designed at CERN

Where is SU-EM involved? Survey for all the Experiments at CERN + ISOLDE and HIE-ISOLDE ATLAS LHC Experiments ALICE ATLAS CMS LHCb and Non-LHC NA61 NA62 CAST Isolde HIE-Isolde All experiments of North and East Areas etc. CMS LHCb ALICE HIE-ISOLDE COMPASS And …

When is SU-EM involved? At all phases of the projects: At very early stage at the design phase Prototyping and tests Manufacturing Pre-assembly Assembly phases of detectors Experiment construction Alignment and positioning phases in the caverns or experimental areas during construction, Technical Stops, Shutdowns, Machine Developments Usual measurement precision (at 1 sigma level) Detector control at manufacturing before assembly 0.03-0.3 mm (max. 0.5 mm) Deformation of detectors under special conditions ~ 0.1 mm Relative position of detectors wrt other detectors < 0.5 mm Absolute position of detectors wrt accelerator geometry < 1.0 mm

Why an involvement at very early stage? Survey work must start at early stage of the project Discussion with coordinators / project leaders / physicists / engineers / designers Define precisely the needs and find reasonable solutions Define all stages when survey will be needed Include alignment to the design (references, integration work) Define local coordinate systems Estimation of the resources needs BUT it is not always the case - last minute (test beams …) SU-EM has also to be flexible, react very fast and propose solutions This is very important Without this survey could be impossible Standards exist / suitable solutions can be discussed

Quick overview of the Survey Toolbox T3000/TC2002 SU software NA2/N3 TOOLBOX Experiment metrology D3X LTD500 Commercial software HDS6200 AT401 + all the associated accessories: retro-reflectors, targets … Line of sight between instrument and object required!

Experiment configuration and survey

Experiments A Russian Doll like configuration What we want to know What we see Many coordinate systems to deal with such as: Sub-detectors, detectors, physics and survey system, CCS …

Geodetic networks

The geodetic networks A Geodetic Network for each Experiment Geometrical Link Machine / Experiment Link to the CCS Materialize the Nominal Beam Line Coordinated work ACC / EM / MTI Allows The positioning of the detectors on the Nominal Beam Line (NBL) The geometrical connection between measurements from the different parts of the cavern

Example: The ATLAS network measurement Geodetic network includes survey galleries System datum in survey gallery Measurements: AT401 laser tracker + Level Network dimensions: 125 m long, 29 m large, 21 m high Summary of results: New points ~150 Stations ~ 44 Observations ~1800 Unknowns ~500 Sigma a post < 0.1 mm Results: HZ (1σ): 1.5 cc VZ (1σ): 3.4 cc levelling (1σ): 0.03 mm distance (1σ): 0.03 mm Problematic factors: Limited line of sights due to detector Walls radial movements ( USA wall: 1 mm/year) Floor heave Height of 20 m => temp. Gradient, steep vertical sighting angles Refraction in survey galleries Precision at level of mechanical adapters

Deep Reference Points (anchored in bedrock) ATLAS Vertical Stability Predictions: -5.5 mm sag, due to weight of ATLAS -2.0 mm sag, concrete contraction (short term) +1.0 mm per year heave, hydrostatic pressure very limited adjustment possibilities for ATLAS predictions have been taken into account for detector placement (assembly TILE-LArg-Solenoid) SKETCH OF FLOOR VERTICAL STABILITY CONTROL PATH Deep Reference Points (anchored in bedrock) Tunnel Levelling Link with cavern floor Optical levelling Measurements: 21 epochs, Aug 2003 – Feb 2014 Linked to deep references Mean heave 0.25 mm/year Max. heave < 3.0 mm in 10 years New values considered for different upgrades

A precise geometry at all stages

During prototyping, tests and construction Ex: CMS TEC +/- (Tracker End Caps) Several photogrammetric measurements at RWTH Aachen during construction phase TEC = 9 support disks for detector elements + 1 Back Disc Each with 4 reference points on circumference Assembly control in vertical position Deformation control in horizontal position

Envelope measurements Ex. ATLAS TRT Barrel – photogrammetric measurement of inner cylinder 16 lines of target tape with 31 targets each Only signalized points 450 Images, 1700 object points, 124000 observations in bundle adjustment Precision 0.06mm in X-, Y- and Z-direction Cylindricity Comparison to measurement with Romer arm by PH/DT Difference to best fit cylinder

Fiducialisation LHCb / Fiducialisation of the 12 IT (Inner Tracker) modules Link between sensitive part and outer references before box closing Measurement in clean room by microtriangulation Angular observations of sensor fiducials Calibrated scale bars White cross on black background of 0.3mm x 0.3mm Illumination by cold light, no optical disturbance Transfer to outer references visible during insertion of all elements in IT box Precision in X-, Y- and Z-direction 0.05mm (1 sigma) Sensor fiducials Outer references

From surface to the cavern Ex. Alignment for ATLAS Pixel detector Extraction of beampipe and Pixel Pixel repair on surface, insertion of IST Insertion of IBL and beampipe in cavern Real scale mock-up for validation Alignment of different tooling Typical relative precision 0.1 mm Laser tracker as major tool

In the cavern CMS Tracker Rails Detector assemblies Detector supports Opening, closing Extractions (Beam pipes …) Insertions Installation of new parts Adjustments Deformation (Loading, movements, B field…) Positioning on the NBL Envelope Cavern stability Etc. Alice Muons ATLAS Network NA62 RICH LHCb Magnet

Ex of a large detector survey in the cavern ATLAS TGC Wheels

Ex of a large detector survey in the cavern ATLAS TGC Wheels Summary for TGC3-C Object diameter ~25 m Distance to object 5-6 m Number of photos ~960 Number of observations ~ 90000 Number of unknowns ~9400 Number of points ~1200 Controls by theodolite Data volume ~ 1.9 GB (jpg) Measurement time in field ~ 1 day Precision ~0.5 mm

Ex of a large detector survey inside the cavern ATLAS TGC Wheels 3D view of object (left) Object points Camera stations Geometry for single point 3D view of object (right) Geometry for single camera

Ex of results for CMS Muon chambers Comparison of muon chamber relative positions using photogrammetry and cosmic ray tracks in the same detector Precision < 0.05 mm

Envelope measurements – 3D scanning A picture of the reality Cloud of millions of 3D points Precision ~3 mm Reverse engineering Preparatory work for design and integration of new projects … Large 3D scanning of CMS (Bulkhead …) DAQ 350 million points Extracted zone: 70 million 3D points ATLAS Extended Barrel DAQ: 100 million 3D points / side After cleaning: 72.5 million 3D points / side

During LS1 All detectors have been opened / closed - several time for some of them Parts have been removed, re-installed (CMS HF, ATLAS SW, …) Detectors have been replaced (Beam Pipes of all experiments, …) New assemblies took place (CMS YE4 in situ, COMPASS DY absorber …) New detectors have been installed / inserted (ATLAS IBL EE, ALICE DCAL …) New instrumentation added (monitoring systems) Survey at all these steps during LS1, most of the time simultaneously, … and also during the run for preparatory work (CMS YE4, ATL IBL …) Not only measurements -> preparatory work, data processing, analysis, reports, results discussion with responsible persons…

Working in the Experiment environment is not only a technical challenge or When the survey becomes a sport

Access and working conditions are not always easy…

Where is the surveyor ?

Looking for some space… ASACUSA Experimental Area

Integrated Alignment and Monitoring Systems

ADEPO (Atlas DEtector POsitioning) Collaboration ATLAS TC / SU Demand: Monitor and speed up closure Gain in precision for re-positioning Relative repositioning at 0.3 mm (1 sigma) Movement follow-up at 0.1 mm Cover 6 DOF per moving detector Cycle < 30 sec. Resist to 1 Tesla magnetic field Radiation dose of 2 Gy for lifetime Status: Algorithms definition done “Near” scale one tests performed Tracing, installation and alignment done Commissioning on going First use: closure at end of LS1 System is based on: 28 BCAMs on feet/rails system 44 passive targets (prisms)

A better idea of the size of pieces to follow within 0.3 mm ADEPO (Atlas DEtector POsitioning) A better idea of the size of pieces to follow within 0.3 mm Somebody is there …

LHCb RICH1 Gas Enclosure and Shielding monitoring Monitoring during magnet ramp-up Proposal of a BCAM based monitoring system Coordination of the project with resources from LHCb Integration / Design / Mechanic / Installation / Cabling DAQ and processing software Integrated to the LHCb control system Movement monitoring from the LHCb Ctrl Room with a precision of 30 microns

LHCb Inner Tracker Monitoring system Goal: Monitoring of the IT chambers during the run Collaboration SU-EM / LHCb Technical Coordination / IT leaders / EPFL Precision demanded 0.1mm for relative movements To be developed and install during LS1 Low material target and support To be monitored IT1 / IT2 / IT3 Suitable configuration found Development of extra synchronised flash for existing BCAMs Light retro targets Integration done Installation on going BCAMs under the IT/OT table and in the VELO area

HIE-ISOLDE Alignment - MATHILDE project Demand: Alignment and monitoring of the Cavities and Solenoids inside the Cryostats Precision along radial and height axis at 1 sigma level over the 16 m: 300 μm for the Cavities 150 μm for the Solenoids Constraints: Ultra high vacuum 10-8 bar Temperature 4K (cryo) Integration Large number of targets NBL +/-300 μm +/-150 μm ~16 m

Precise 5° inclined viewports R&D for MATHILDE New passive targets Collaboration with Technical University of Liberec / Toptec (CZ) Very special glass Tested in high vacuum Tested at 5K Courtesy of: Y. Leclercq (TE-MSC), E. Urrutia (EN-MME), G. Vandoni (TE-VSC) Precise 5° inclined viewports Status The hardware study is completed The MATHIS DAQ, preprocessing and processing software is well advanced The first system should be ready for spring 2015 First installation in HIE-ISOLDE, next summer New HBCAMs Collaboration with Brandeis University (US) Same precision than BCAM (5urad relative, 50urad absolute in camera mechanical system) Large field of view Calibrated laser and Synchronized flash

R&D – An opportunity to develop partnerships For projects in the frame Experiments: Projects in collaboration with the Technical Coordinations EPFL (LHCb IT project) ETHZ and Etalon (PACMAN) For some optics projects Institute of Plasma Physics (CZ) (Interferometry) For HIE-ISOLDE Development in the frame of the CATHI project Associated partners: Liberec University / Toptec (CZ) Brandeis University (US) It is also a lot of interactions with: Physicists Project leaders Integration Design Mechanics Vacuum Cryo experts …

A Team to face the challenges

The SU-EM Team members (LS1)

The composition of the Team (LS1) 6 Staff 5 persons from LHC Exp. Collaborations (LS, TS) 2 PJAS (EN-PH) (LS1) 1 FSU (up to end 2015) 3 C201 Industrial support (LS1 period) 1 PhD student PACMAN project (up to 2016) In total 18 persons during LS1 At the end of LS1 ~9 persons will stay Many thanks to the Collaborations and to PH Department Their contribution to resources is of the upmost importance

ATLAS Outstanding Achievement Award for Dirk, Vitali, Nikolay and Mikhail “… The team from the Joint Institute for Nuclear Research Dubna -- Nikolay Azaryan, Vitaly Batusov, Mikhail Lyablin – and Dirk Mergelkuhl of CERN were recognized for their contribution in the alignment and survey work on almost all of the ATLAS detector components and supporting structures. …” Extract from the article: http://atlas.ch/news/2014/ATLAS-Awards-Achievements-in-Run-1.html

The future

ALICE Upgrade for LS2 New ITS (the largest HEP pixel detector ever, 7 layers, ~11m2) Replacement of TPC endplates New central Beam Pipe LHC Exp Upgrade information from Werner Riegler lecture TPC ITS and Beam Pipe

ATLAS Upgrade for LS2 New Small Wheels New JD LHC Exp Upgrade information from Werner Riegler lecture New Small Wheels New JD work in surface for the construction assembly and fiducialisation Installation and adjustment in the cavern

LHCb Upgrade for LS2 IT and OT Inner and Outer Tracker  FT LHC Exp Upgrade information from Werner Riegler lecture IT and OT Inner and Outer Tracker  FT + Integration of monitoring system Change of central ECAL modules TT Trigger Tracker  UT Change RICH HPDs VELO

CMS Upgrade for LS2 New Muon Chambers LHC Exp Upgrade information from Werner Riegler lecture New Pixel detector (ready for installation in 2016/17 Year End Technical Stop) HCAL upgrade: photodetectors and electronics (HF 2015/16 YETS, HB/HE LS2)

CM1 Tshield assembly in Clean Room HIE-ISOLDE – Stage 1 From now to Sept. 2015 adjust supports & jacks geod. Netw. Upgrade 3 (finish before HEBT elements install) alignment elements at installation transfer line measurement (when elements in place) transfer line 1st alignment transfer line smoothing Follow-up for CM1 assembly adjust CM1 & intertank sectors commissioning monitor alignm system (CM1) follow-up cav. Sol. Position during vac pumping Follow-up for CM2 assembly adjust CM2 & intertank sectors commissioning monitor alignm system (CM2) CM1 Tshield assembly in Clean Room Stages 2 (CM3/4) and stage 3 (CM5/6) + Linac completion -> Work up to 2019

CONCLUSION

CONCLUSION Survey for all the experiments at CERN (included in the MoU of Exp.) SU-EM is present: During construction, Technical Stops, Shutdowns, Machine Developments During the run periods for preparatory work, tests, assemblies… A part the precision the challenges are Managing the simultaneity of the tasks in the different experiments Working in a constantly changing environment Dealing with large objects in narrow spaces Dealing with a lot of co-activities in a same area Data processing and result publication

CONCLUSION Working in experiments requires the integration of aspects such as: The knowledge of the experiments and their complexity The planning, the sequences of assembly and of opening/closing The survey expert in charge of each Experiment must be capable of Flexibility, creativity, autonomy, fast analysis and decision taking It is important to work with well trained persons Direct contacts with responsible persons are essential Technical Coordinators, Project Leaders, Project Engineers, Physicists At CERN and in the Institutes of the Collaborations Future will be busy: T-Stops, preparatory work for LS2 and LS2 period

THANKS FOR YOUR ATTENTION