LHC FBs - weekly meeting

Tuesday 31 Mar 2020, 09:30 → 10:20 Europe/Zurich

Skype

Meeting Date: 31-Mar-20 09:30

Location: Skype

Link to Outlook Item: click here

Invitation Message

Participants

Diogo Miguel Louro Alves (Meeting Organizer) - present

Leander Grech - present

Andrea Calia - present

Michi Hostettler - present

Jorg Wenninger

Stephen Jackson - present

Notes

• Status of actions from last meeting:
  • DA + LG: sanity check of twiss parameters - not done
    • can implement min/max checks in server action and create corresponding shm fields and value-items
    • start with very permissive min/max values until more realistic ones have been specified by OP
  • DA + LG: concentration elements vs feedback elements - ongoing
    • Calculating RMs with less BPMs is incompatible with the bootstrap file, therefore, in order to complete this action, first we need to eradicate the bootstrap file from BFCLHC - done
    • Read extra-column in BPM2CRATE.mapping with boolean stating whether each BPM should be used for FB or not - ongoing
    • Calculate RM taking into consideration the info in the aforementioned column - ongoing
  • DA: create indico pages to hold notes and docs for weekly meetings - done

 

• BI updates from last meeting:
  • DA: reported on the status of BI work, i.e., work status on the actions from the previous meeting. In particular, BPM and COD mappings are now exclusively driven by the mapping files.
  • LG: asked for OP to provide a new mapping file with the extra column
  • Action - AC: create new mapping file with extra column

 

• OP updates from last meeting:
  • AC: start working on the feedbacks towards the end of this week. Start by providing the new BPM mapping file and then continue working on the implementation of the list of desired tests.
  • MH: from the last BFCLHC commit, the test comparing the RM with YASP failed. Most likely the reason for this is that the modifications done in the java IDE (BPMWF BPMs were originally not used by YASP) did not propagate to the docker JAVA infrastructure

 

• BPMR.5L8.B2:
  • New twiss data
    • MH: upload of twiss data to LSA will be done before the 2021 startup.
  • Update mapping
    • DA: BPM2CRATE.mapping file will need to be updated
  • Logging metadata
    • DA: we have to be careful with the backward compatibility of logged data if we have to change this metadata
    • SJ: logging database have a mapping file in CALS for the metadata - coming from an old file from Eva
    • SJ: suggested to get in contact with Jakub Wozniak and ask about the management of the metadata of the BPMs and how to proceed (keeping in mind backward compatibility also in the move from CALS to NXCALS) just like it's already being addressed for the BLMs - Action for DA

 

• Planning:
  • Meet next Tuesday

 

• AOB:
  • SJ: received email from Aurelien Poscia to change PPM settings of RefQQP property in the BFBLHCSettings class - Action for DA
  • SJ: Georges-Henry will join BI-SW to work mostly on BLMs but said he could contribute (probably not on the Fesa side) to the LHC FBs, since he's familiar with the system

09:30 → 09:40 Update from BI (including actions from last meeting)

Speakers: Diogo Miguel Louro Alves (CERN), Leander Grech (University of Malta (MT))

09:40 → 09:50 Update from OP

Speakers: Andrea Calia (CERN), Dr Jorg Wenninger (CERN), Michi Hostettler (CERN)

09:50 → 10:00 BPMR.5L8.B2

Quoting M. Krupa:

"The cryogenic Beam Position Monitor BPMR.5L8.B2 installed within the cryostat of the standalone quadrupole LQNMA.5L8 has developed a nonconformity leading to the loss of reliable beam position measurements in the vertical plane. A direct intervention on the faulty BPM has been excluded as it would require delicate and non-standard handling of the magnet. It is therefore proposed to install a new warm BPM adjacent to the LQNMA.5L8 in the LHC vacuum sector A5L8.R.

A cold BPMR.5L8.B2 could not be used during the Run 2 due to a major asymmetry in the vertical plane. During LS2 we confirmed that the problem is caused by the cabling inside of the magnet cryostat. Unfortunately, fixing this problem would be extremely challenging so it it was decided (by BI, TE/MSC and LMC) that a better solution would be to install a new warm BPM just next to the magnet.

The idea is to completely disconnect the BPMR.5L2.B2 and reuse its cables and acquisition electronics for the newly installed BPM. The BPM will be of a different type (BPMWI instead of BPMR) and at a slightly different longitudinal position so the calibration coefficients / polynomials and the layout database will need to be updated. So far I have focused on the hardware aspects of this intervention but I would like to check with you if you see any problems concerning the BPM software and / or the orbit feedback system?"

10:00 → 10:10 Planning

10:10 → 10:15 AOB