ArcHalfCellMock-up Meeting - Alignment and Stability #2

Thursday 21 Jul 2022, 14:30 → 15:30 Europe/Zurich

Federico Carra (CERN)

Notes of Meeting Arc Half Cell Mockup – Alignment and stability #2

21^th July 2022

List of people attending the meeting: 

F.Carra (chaiman), K. Artoos, L. Baudin, M. Guinchard, K. Oide, Rogelio Tomas Garcia

Slides of the presentations are available in the Indico page related to the meeting (https://indico.cern.ch/event/1184705/ )

Agenda:

1. Opened discussion (all)

 

1.  

Federico recalled that considering the alignment procedures is one of the deliverables of the mock-up project.  
“Supports and stages and access to the components should consider alignment procedures”

 

Federico showed the table of alignment requirement presented at the FCC week by Tessa Charles.

On top of the static alignment tolerances, Federico recalled the objective of “no vibration mode below 100 Hz”, “magnet must follow the ground motion”, mentioned by Katsunobo at the 1^st FCC arc half-cell meeting.

 

Mickael: rather than requirement in terms of natural frequency, we need to know the admissible magnet centre motion on a given range of frequency: for instance, a PSD giving the admissible level as a function of the frequency.

Rogelio understands the request but does not know of any study dedicated on FCC project.

 

Katsunobo showed presentation for FCCIS WP2 Workshop 2021 (https://indico.cern.ch/event/1085318/timetable/ ) about vibration tolerance for IP and arc magnets and feedback performance criteria.

The vertical displacement of a beam caused by a quadrupole vibrating with a given amplitude

Taking into account simplified model of ground motion defined by formulation. Consistent with measurement at LAPP and LHC

“Assuming each quad follows the ground motion” 

Optical simulation at the IP have been performed based on the hypothesis of no amplification of the motion by the support or girder.

 

 

Should the requirement concern Arc magnets or ones close to Interception Points? Both

 

 

Actions follow up:

1. Creation Indico Page, Upload Katsunobo Presentation 

à Lucie

1. People to be included in the discussions on that topic: 
   1. Phil Burrows? About Beam/Beam Feedback
   2. Jorg Wenninger? For opinion about requirement based on experience from HL-LHC
   3. People from LAPP ? Presenting results on mechanical stability in FCCIS Workshop (https://indico.cern.ch/event/1085318/timetable/)

14:30 → 14:50 Introduction on the need for alignment and stability requirements for engineering design

The objective is to build-up a consistent set of specifications that we can then use as a reference for the next part of the study concerning the system stability.

Speaker: Federico Carra (CERN)

14:50 → 15:10 Presentation of preliminary results on vibration effect on beam properties

Speaker: Dr Katsunobu Oide (High Energy Accelerator Research Organization (JP))

VibrationTolerance_Oide_211203.pdf