HL LHC survey

Monday 27 Oct 2025, 10:00 → 11:00 Europe/Zurich

30/2-040 (CERN)

all installation drawings for LSS1 L1 ordered.pdf

HL-LHC survey needs for installation.pdf

HL-LHC survey needs for installation.pptx

HL LHC Survey overview.pdf

Non-beam tracing summary.xlsx

Overview of beam elements to mark on floor 22 09 2025.pdf

PBS HL LHC and survey.pdf

Survey & Alignment - WP15.4

Meeting Minutes

1. Beam Elements

• BE GM uses the layout database as input in their software; installation drawings will be used to validate that the inputted values from the layout database are correct and to cross check the traced values on-site.
  → Action: BE GM to verify that installation drawings align with layout database inputs. à not sure that they will cross check all the values of the drawings with the layout database, I understood that they use the drawings mainly for quality check of the tracing on-site.

 

• LSS1L installation drawings will be reviewed by BE GM to ensure all points to be marked are described.
  → Action: BE GM to check LSS1L installation drawings, note any missing information or comments, and  WP15 propagate findings to other straight sections.

 

• WP15 will provide an Excel spreadsheet containing the full inventory of beam elements and related equipment to be installed.
• This spreadsheet will serve as a central umbrella document linking:
• Beam elements ↔ layout database references
• Minor Civil Engineering Works (MCEW) to be completed to allow jack installation
• Installation drawings of the equipment
• The spreadsheet will be a living document and a reference tool for BE GM.
  → Action: WP15 to prepare and share the Excel “umbrella” inventory spreadsheet: 
  https://edms.cern.ch/document/3376202 

 

• Labelling: When layout database references are too long, BE GM, in collaboration with equipment owners, will create shorter labels, recorded in the spreadsheet for consistency.
  → Action: BE GM to define shorter, traceable labels within the Excel file, in collaboration with equipment owners. à to be discussed also with Paolo and Joao Oliveira. I understand the concern regarding the naming, but it is also a shame not to be consistent with what is already indicated in the drawings…

 

• Mechanical drawings: WP15 will check with equipment owners for availability.
• These drawings must complement installation drawings by including:
• Distance between jack head and beam line
• Survey target positions
• Anchoring points
• Cold mass and midpoint positions

à I think all this was already present in installation drawings, to be repeated also in Mechanical drawings?

• These drawings will also be added to the Excel spreadsheet.
  → Action: WP15 to contact equipment owners and collect mechanical drawings.

 

• TAXS installation is out of scope for the accelerator team’s survey.
  → Action: WP15 confirm TAXS marking to be handled by the survey team for experiments.

 

• Pillars for Q1 will be marked manually, due to the cylindrical surface that prevents use of the robot.
  → Action: BE-GM to mark Q1 pillars by hand. à this can be considered beam component marking as it is for the jacks of Q1

 

• DFXI and LDQD (DCM): There is a request to mark supports, but designs are still preliminary.
  → Action: WP15 to check with Luca if marking support points can be added with the current design.

 

 

• DFMI supporting structure: As an element supported from the vault, follow the non-beam element process.
• These marking points should not be included in the installation drawings prepared by Luca.
  → Action: Exclude DFMI vault-supported points from beam element installation drawings.

 

• Crab Cavities: In addition to jack locations, the FPC axis should be marked on the floor.
  → Action: Confirm with Teddy that FPC axis marking is required.

 

• Roman pots (PPS2-Totem): trace ‘entrée/sortie’ as for the other beam components, instead of the support plate extremities.

 

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2. Non-Beam Elements

• A reference line at 1.5 m from the floor (height value to be confirmed with final tunnel integration 3D models, beginning 2026) will be marked on the vault side of the QXL/QRL.
  → Action: WP15 will add reference line for non-beam elements in the documentation as specified.

 

• WPS (wire positioning system) pillars of BE-GM-HPA are another non-beam element.
  → Action: BE GM to check with colleagues to make WPS pillars available in Luca Gentini’s installation drawings à these pillars were already considered to be marked, what is missing is their presence in the installation drawings. In principle, they were supposed to follow only the non-beam components workflow, which does not include installation drawings.