ETO Task Force meeting

Monday 3 Mar 2025, 14:30 → 16:00 Europe/Rome

https://cern.zoom.us/j/61274255815?pwd=2fwGbaMrZAYmUfpUfMCjKwpoYzPCKd.1 (remote)

Fiodor Sorrentino (Istituto Nazionale di Fisica Nucleare)

Zoom link

Rolling agenda

250303_Agenda_Taskforce_Meeting.docx

250303_Minutes_and_Actions_Taskforce_Meeting.docx

Taskforce Weekly Plenary Meeting  
Agenda, 3 March 2025  

Meeting time: 14:30 – 16:00 CET  

Zoom meeting room:   

Zoom link 

  

Attendees: All task force members 

 

Chair: Fiodor Sorentino 

Key Takeaways: 

• Cleanliness requirements and procedures for towers/payloads discussed, with action to verify clean room sizing in detector layout 

• Tower categorization and options identification work ongoing, to be completed before Amsterdam meeting if possible 

• Noise budget simulations presented, including "worst case" scenarios without filter cavities 

• Proposed agenda for Amsterdam meeting shared, with focus on detector layout and carbon reduction 

• New tools introduced: action item tracking spreadsheet, glossary/acronyms in Overleaf doc, civil engineering cost estimation tool 

Next steps/actions: 

• Complete tower options identification if possible before Amsterdam 

• Prepare for tunnel diameter reduction discussion at Amsterdam meeting 

• Add PISA meeting action items to tracking spreadsheet 

• Start using glossary/acronym functionality in Overleaf document 

• Expand civil engineering tool to include tunnels 

• Refine criteria for civil engineering cost estimates 

 

• Update on tower categorisation 

14:30-14:50 CET 

 

Point presented by: Romano Meijer 

Point submitted for: information 

 

Summary of discussion: 

Romano provided an update on the work to categorize and map the different tower components and nodes onto the optical layout. This includes incorporating the periscope towers and high frequency test masses. The task force members agreed to continue this work offline, focusing on completing the quantification of residual motion and mapping the vacuum vessel requirements. There was also discussion of the need to consider integrated tower concepts that optimize across the different subsystems. 

 

Takeaways: 

• Romano updated categorization based on PISA discussions and new optical layout 

• Separate category added for high frequency test masses 

• Options for different categories still need to be summarized 

• Aim to complete options identification before Amsterdam if possible 

• May need dedicated session on tower integration in Amsterdam 

 

 

• Clean rooms needs from cleanliness requirements 

14:50-15:10 CET 

 

Point presented by: Piero Rapagnani 

Point submitted for: information 

 

Summary of discussion: 

Piero provided an overview of the key challenges with maintaining cleanliness for the optical components, including fiber damage from dust and particles, absorption issues, and stray light. He outlined the typical clean room setup and procedures used, emphasizing the importance of a multi-step cleaning process starting from the initial component preparation through final assembly. The task force members discussed the difficulty of maintaining cleanliness, especially during critical assembly steps, and the need to further investigate the specific particle size distributions that pose the greatest risk. 

 

Takeaways: 

• Piero Rapagnani presented on cleanliness needs for towers/payloads 

• Key risks: fiber damage from particles, point absorbers on mirrors, increased stray light 

• Particles >10 μm most dangerous for fibers/mirrors 

• Clean room class ISO 5 (old Class 100) recommended minimum 

• Detailed cleaning procedures outlined, including ultrasonic baths and washing tunnels 

• Action: Verify clean room sizing in detector layout with Piero/Antonio 

 

 

• Update on noise budget 

15:10-15:25 CET 

 

Point presented by: Valeria Sequino 

Point submitted for: information 

Summary of discussion:  

Valeria summarized the ongoing noise budget analysis, including the sensitivity curves provided to the US team for review. The task force members discussed the need to analyze both nominal and worst-case scenarios, and to ensure the parameter ranges used are reasonable and aligned with the science case requirements. Further work is planned to incorporate the impact of suspension and cryogenic temperature on the noise budget. 

 

Takeaways: 

• Valeria presented sensitivity curves for various scenarios, including: 

• Different filter cavity lengths 

• Temperature variations 

• Residual gas pressure changes 

• "Worst case" scenarios without filter cavities 

• Ongoing work on suspension thermal noise, input mode cleaner length impacts 

• Science case analysis of curves to be done by Francesco Ulana 

 

 

• Draft agenda for the Amsterdam meeting 

15:25-15:35 CET 

 

Point presented by: Fiodor Sorrentino 

Point submitted for: information 

 

Summary of discussion: 

Fiodor presented a proposed agenda for the upcoming in-person meeting in Amsterdam, suggesting more time for plenary sessions and flexibility in the parallel session topics. The group discussed the need to focus on reducing tunnel volumes as a key cost driver, as well as adding dedicated sessions on tower integration and tunnel diameter optimization. There was also agreement to mark some parallel sessions as optional to allow for flexibility. 

 

Takeaways: 

• Proposed 3-day agenda shared, with mix of plenary and parallel sessions 

• Focus on 2L detector layout, cavern volume reduction, system decomposition 

• Suggestions to: 

• Add session on tunnel diameter reduction 

• Mark some parallel sessions as optional/flexible 

• Include tower integration session 

 

 

 

• Software tool for civil engineering 

15:35-15:50 CET 

 

Point presented by: Wissam Wahbeh and Jonathan Bratanata 

Point submitted for: information 

 

Summary of discussion: 

Wissam demonstrated a parametric model being developed to estimate civil engineering costs based on the detector layout. The tool allows for interactive exploration of how changes to the layout impact the calculated volumes and costs. The task force members agreed this would be a valuable tool to use during the Amsterdam meeting. 

Takeaways: 

• Civil engineering cost estimation tool demonstrated: 

• Parametric model of caverns/volumes 

• Can calculate volumes and costs based on layout changes 

• To be expanded to include tunnels before Amsterdam 

 

 

• List of action items and glossary for Overleaf document 

15:50-16:00 CET 

 

Point presented by: Benoît Tuybens 

Point submitted for: information 

 

Summary of discussion: 

Benoît provided an overview of the new action item tracking spreadsheet, and the glossary/acronym features added to the Overleaf document (by Nathan Holland). The task force members were encouraged to utilize these tools to maintain visibility and consistency in the work. 

 

Takeaways: 

• Action item tracking spreadsheet set up 

• Glossary and acronyms functionality added to Overleaf document 

 

14:30 → 14:50 Update on tower categorisation

Speaker: Romano Meijer

14:50 → 15:10 Clean rooms needs from cleanliness requirements

Speaker: Piero Rapagnani (Istituto Nazionale di Fisica Nucleare)

2025_03_03_ET_Clean_Rooms_a.pptx

15:10 → 15:25 Update on noise budget

Speakers: Valeria Sequino (INFN sez. Napoli, Università degli Studi di Napoli "Federico II"), Valeria Sequino (ROMA2)

20250303_NoiseBudgetUpdate_ValeriaSequino.pdf

15:25 → 15:35 Draft agenda for the Amsterdam meeting

Speaker: Fiodor Sorrentino (Istituto Nazionale di Fisica Nucleare)

Task force Amsterdam meeting agenda eigth weekly meeting-3.pdf

15:35 → 15:50 Software tool for civil engineering

Speakers: Jonathan Bratanata (Nikhef), Wissam Wahbeh

15:50 → 15:55 List of action items

Speaker: Benoît Tuybens (Nikhef - ETO directorate)

15:55 → 16:00 Glossary for Overleaf document

Speaker: Benoît Tuybens (Nikhef - ETO directorate)