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

2. 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

3. SU section and Experiment Metrology Unit

4. 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

5. 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

6. 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 …

7. 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 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

8. 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

9. 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!

10. Experiment configuration and survey

11. 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 …

12. Geodetic networks

13. 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

14. 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): mm
distance (1σ): 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

15. 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

16. A precise geometry at all stages

17. 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

18. 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, 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

19. 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

20. 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

21. 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

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

23. Ex of a large detector survey in the cavern
ATLAS TGC Wheels
Summary for TGC3-C
Object diameter ~25 m
Distance to object 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

24. 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

25. 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

26. 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

27. 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…

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

29. Access and working conditions are not always easy…

30. Where is the surveyor ?

31. Looking for some space…
ASACUSA Experimental Area

32. Integrated Alignment and Monitoring Systems

33. 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)

34. 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 …

35. 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

36. 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

37. 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

38. 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

39. 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 …

40. A Team to face the challenges

41. The SU-EM Team members (LS1)

42. 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

43. 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:

44. The future

45. 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

46. 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

47. 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

48. 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)

49. 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

50. CONCLUSION

51. 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

52. 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

53. THANKS FOR YOUR ATTENTION