Minutes from 3rd ALICE & VSC LS2 preparation meeting

Participants: Arturo Tauro <Arturo.Tauro@cern.ch>; Corrado Gargiulo <corrado.gargiulo@cern.ch>; Werner Riegler <Werner.Riegler@cern.ch>; Antonio Lafuente Mazuecos <antonio.lafuente@cern.ch>; Giuseppe Bregliozzi <Giuseppe.Bregliozzi@cern.ch>; Jerome Gilles Chaure <jerome.chaure@cern.ch>; Chiara Di Paolo <chiara.di.paolo@cern.ch>

1. LS2 planning update

• Exchange of the bottle for GIS injection can be performed during TS3.
• IP2.X; A1R2.X and A1L2.X vented by dry air or nitrogen (to be decided by VSC).
• Removal of the RB24 can theoretically start on 4th of December (please see "LS2 detail schedule notes" - bellow minutes - part B).

2. LS2 Installation procedure

BVO will meet with Corrado and Antonio in order to discuss in detail new installation procedure for LS2 VC2C. Meeting scheduled for Tuesday 5th of June by Josef. Draft of the installation procedure by the end of June / beginning of July.

3. LS2 Coordination

Based on request of Marzia Bernardini, we need to present detail planning to the LHC coordination. Plan will contain all the details about the access on UX and machine side as well as information about cabling deadline and foreseen x-rays/survey inspections.

Post-meeting remark (JS): Meeting should takes place on 25th of June 15:30 at 112-4-B60.

4. Production update

Schedule still valid. VSC is working on acceptance of the NEG coating qualification samples (once finished, we send notification also to ALICE).

5. Annular ion pump VPIXB

As presented the annular ion pump has negligible effect on the vacuum performance in IP2.X. As the ALICE takes care about the secondary vertices close to the VVGMT manual valve, VSC propose to suppress the pump. We will keep the old pump as spare including drift chambers for both layouts (with and without the pump). ALICE will decide whether to keep it or drop it.

6. Non-baked IP study

In order to evaluate need of remote bake-out oven for beryllium part of the VC2C (bake-out during standard access regime - TPC in run position - no access on the omega platform and compensator side) BVO has performed the pressure profile simulations assuming the non-baked beryllium part (with saturated NEG). Results shows static pressure bellow 1e-10mbar which is still acceptable for the OP. BVO will study dynamic effect of upper mentioned. We will also investigate whether and how we can build the remote baking system, what are the risks and constraints. ALICE will decide whether the system is needed or not.

7. Next meetings

• Short meeting giving update on 5 & 6 by end of June.
• Next review by September.

---- POST MEETING NOTES ---

A) Email from Arturo 07/06/2018

• VPIXB to be dropped.
• Remote bake-out system to be kept.

B) "LS2 detail schedule notes" (Josef Sestak)

• 03/12 Start of LS2
• 03/12 Venting of the IP2.X with N2 or dry air.
• 03/12 Closing of the VVGMT in the mini-frame.
  • uncommissioning of the cabling for vacuum equipment in RB24 (VGRB.89.1L2.X; VGI.89.1L2.X; VPIA.89.1L2.X; VPIXB.45.1L2.X - cable suppressed; VVGMT.43.1L2.X; VGRB.42.1L2.X - cable suppressed)
  • cabling on the LHC side stays connected - no access - VGPB.190.1L2.X - disconnected in the rack;
  • Pre-requisites for vacuum activities:
    • ADA must be dismounted;
    • ZEM must be dismounted;
    • BLMEI.A1L2 must be dismounted;
    • BLMEI.B1L2 must be dismounted;
• 04/12 Dismounting of the A1L2.X - RB24 part (phase 1).
  • Chambers stored in the mini-frame area up to the 06-07/12 (lifting of the mini-frame celling).
  • Box to the UX25 by crane. Chambers will be stored in the box and taken out to the SX RP zone.
  • VVGMT stays in place (blank flange)
  • VC2UD.173.1L2.X chamber stays in place with blank flange.
  • VC2UC.A1L2.X squeezed chamber stays in MBWMD magnet (to be filled with N2 and pinched-off).
• 17/12 Dismounting of the A1L2.X - RB24 part (phase 2).
  • Dismounting of the VC2UD.173.1L2.X
  • Pre-requisites for vacuum activities:
    • ADA must be dismounted;
    • Additional wall plug shielding must be removed by ALICE;
  • Vacuum supports must be removed including green rail structure (ALICE or VSC?).
  • Chamber with the accessories can be directly moved to the SX RP zone.