GAS M&O meeting 09 December 2019

Present: Beatrice, Roberto, Fred, Patrick, Kacper, Andrea, LPh, Gianluca, Mara, Federico, Fabio

Indico: https://indico.cern.ch/event/868910/

ALICE #no elog

• MTR
  • Alarm in power supply: DC MCB trip —> Michal/Patrick to check
  • This week and next week: tests with GC/MS

Reminder:

• mixer pressure regulation does not work: Zimmerli not installed
• exhaust pressure regulation does not work
• CPV
  • Start to reconnect the detectors but in few channels there is overpressure, probably coming from the pipes: LPh is investigating
• TPC
  • Still leak present
  • Regulation valve of the pump is fluctuating a lot: very high PID —> LPh/Michal to fix
• MCH
  • System restarted
• TRD
  • Alarm on power supply

Reminder

• Purifier: safety valve at the input where we have Ar or Ar/H2 at high pressure —> LPh to check with safety
• Purifier: to review if keep the safety valve or the rupture disk

ATLAS #2118

• CSC

Reminder:

• After the power-cut there was not communication with PLC: damage of differential circuit breaker —> to repair
• MDT
  • Rack 63: again problem on one channel reading: at this point is not the ELMB/motherboard but an electrical problem —> Michal/Patrick to investigare 
  • Pump + H2O analysis logic: to discuss with Michal

Reminder:

• In general: several problems with pressure sensor in MDT. Patrick said to add a resistance in the channel
• RPC
  • One membrane of the pump broke after 1200 hour
  • Flow reduced to minimum with the zimmerli to decrease input pressure form ~10 mbar to 3 mbar
  • Rack 65: PT6526 is miscalibrated. It reads -0.4 mbar when the system is in stop or in back-up
  • Rack 62: zimmerli of back-up too high. It created a shock on the chamber of ~ 2mbar —> back-up pressure reduced
• Xmas holidays
  • Only TFC and MDT will run: to stop on the 5th
• w2 and w3 2020: general power-cut: piquet to stop the system on 05 January

CMS #2114

• RPC
  • Presentation from Gianluca/Sabino about CMS RPC status
  • https://indico.cern.ch/event/868910/contributions/3663039/attachments/1958743/3254641/CMS-RPC_gas_meeting_20191208_1.pdf
  • All dummy chambers ready
  • ON: all barrel
  • ENDCAP: several problems (see Gianluca’s presentation)
  • Rack 85: to check if dummy chamber is installed, if yes to add pressure sensor connection
  • Reminder:
  • Missing quick manifold and flowcell in barrel +1 and +2
• DT
  • Difficult to re-start the gas system after power-cut —> to do some tests

Reminder:

• Test for power cut and re-start for the exhaust line —> to do other tests
• CSC

Reminder:

• Warning to set-up —> Beatrice/Michal/Roberto
• GEM
  • Ga system working fine
  • Rack 61 with detector, rack 62 with all by-pass
  • Flowcells problem in rack 61: ch 3, 5, 7, probably a leak in the connectors of the patch panel of GEM —> Mara to check with Daniel
• R134a recuperation
  • To understand logic in case of presence of leak/iC4H10 —> Roberto/Nicola Broca

LHCb #2119

• RICH1
  • in Run with CO2
  • Mara to prepare a summary for Air contamination

Reminder

• Re-fill with CO2 but we take 600 ppm because the pump took Air —> to think what it can be done to avoid Air intake at the re-start of the system
• RICH2
  • < 1% of CF4 —> stop the system and leave in back-up for Xmas holidays
  • To do a O2/N2 measurement before the stop —> Mara
• SciFi
  • Commissioning on-going

PIQUET

• General power-cut

GENERAL

• Xmas status of gas systems: only ATLAS done
• Xmas gas consumption: missing ALICE
• To prepare all pipes for the membrane pumps to put in place —> Kacper