Feedback from un-collaring of VS-10 (MBRD5)

Wednesday 13 May 2026, 15:00 → 17:00 Europe/Zurich

 

• collar packs were removed one by one, verifying the pressence of the of the short applying 1 kV test after each collar pack was removed.
• the short it is located at the interface between the first turn block and the first wedge. The wedge insulation in that region appears to be completely cut.
  • This is a point where we have already experienced similar issues in the past (in the multiple collaring attems of VS-06 in MBRD3,
    https://edms.cern.ch/document/3087008
    ), which we believed we had resolved by prescribing the application of additional Kapton tape in all areas where the wedge insulation appears damaged. In this case, however, it was not sufficient, probably because the macroscopic damage was not present on the bare coil and developed during subsequent operations

• the short it is located close to the end of the kapton tape re-informent 

• Next steps ASG
  • Asses the damage on all components, including ground insulation all along the coil, identifying areas where the insulation is marked 
  • May 22nd a meeting to agree on the procedure for completing magnet 5 and mitigate this issue in future collaring operations
    • the preliminary proposal is to apply additional kapton tape, to be discussed with CERN colleagues if there is further feedback
  • the idea then is to go ahead with magnet 6 collaring and in the meantime agree on waht to do with magnet 3
  • They have ground insulation to make 4 apertures, INFN will procure more
    • add 3 apertures of ground insulation (6 kCHF/insulation set)
  • Collaring shoes are in a good sahep from VS-10, most of them can can be re-used. They have collaring shoues only to do the 2 apertuers of magnet 6. 
    • 1 steel sheet (10 kCHF)