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Gas systems weekly project meeting
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Europe/Zurich
32/1-A24 (CERN)
gas systems project meeting
Gas systems
Gas systems
Key Outcomes
The meeting covered operational issues across multiple detector gas systems (RPC, CSC, MDT, TPC, CLOUD), reviewed upcoming LS3 project work for Atlas, and addressed alarm management, PLC replacement planning, and gas consumption changes. Key decisions were made on the ATLAS MMG upgrade date (November 12) and ATLAS RPC rack 61 refurbishment timeline starting mid-November. Gas consumption was reduced across several ATLAS systems, and CLOUD was presented.
Decisions Made
· Alarms LINAC4 152 and 400 removed from the piquet; leak-from-bottle alarm retained as critical
· PLC replacement from Siemens to Schneider to be planned; functional analysis and software review required beforehand
· ATLAS MMG upgrade confirmed for November 12; one day for PLC loading, one week for testing
· ATLAS RPC system stop planned for first week of January for software upgrades and RAck 61 rack reinstallation
· ATLAS RPC exhaust pressure alarm threshold Kc to be raised from 5 to 10 (previously set to 5 after changing from 1)
· Atlas RPC systems stop planned for first week after return in January (January 5–6)
· Passed to 100% argon for ATLAS MMG; decreased TGC and MDT input flows
· Gas bottle calibration procedure: procedure reviewed. Mark bottles as "empty" in the system if no longer in possession
Completed
· CLOUD new humidification system installed with automatic water trap (two-level filter, fully automatic emptying)
· CLOUD mist system upgraded to two mists (previously one); both modes (filling and run) documented
· Component location file (Excel, zone-based) created for CLOUD maintenance reference
· CMS old pipes removed; new pipe connections and stickers in progress; new filter support started in UXC
· Freon already moved to backup supply at Point 1; BE group move planned
Blockers
· MDT stop required for exhaust pipe cutting work; duration uncertain (target ~1–2 hours)
· Nitrogen and argon systems must stop when flexible pipes are removed at Point 1
· ATLAS RPC Rack 61 electrical commissioning cannot proceed until data cables are pulled by technical coordination — earliest January, likely February–March
· ATLAS RPC Regulation valves installation also blocked on cable availability from technical coordination
· ATLAS RPC Secondary RPC mixer blocked: dependent on new lines from technical coordination (March–April)
· CLOUD P&ID (mechanical and electrical) incomplete; electrical cabinet 3 to be done; mechanical main diagram needs cleaning
Pending Confirmation
· CMS CSC +3 disconnection (9 channels) caused unexpected pressure drop; follow-up call needed to determine cause
· Gas bottle calibration emails: confirm sender identity and cross-check bottle lists; reply to flag non-working procedure steps
· R1233ZE new gas line for Atlas RPC: meeting needed with Paolo and team — testing period required before operational use; not confirmed for RUN 4
· Distillation unit relocation near second mixer and purifier: Nicola Broca availability to be confirmed
· ALICE TPC filter replacement: pollution found in loop; new pickups to be built; DTC intervention needed
· Non-LHC experiment support policy (e.g., CLOUD, LINAC4): strategy review needed with new group leader
· FSU manpower numbers per ticket not finalized; Andrea to update planning once numbers confirmed
Risks / Escalations
· CLOUD valve stuck at −26°C: valves can seize when temperature is negative (move by ~1 mm); team reminded to always check temperature before intervention
· Helium bottle installation for leak test (CLOUD): borderline scope for piquet non-LHC support — flagged but not escalated
· ATLAS Battery change frequency doubled (every 10 days vs. 20) due to CO2 input flow reduction
Action Items
· Andrea: Call back regarding CMS CSC +3 disconnection and pressure drop investigation
· Roberto: Contact Nicola Broca : distillation unit relocation availability
· Max: Update ticket dates to reflect November 12 start; ensure planning tool auto-updates
· Davide/Max: Cross-check FSU manpower estimates per ticket with Andrea for planning update
· Patrick/Maria Cristina: Reply to calibration email flagging non-working procedure steps
· Roberto: follow up on strategy question on non-LHC experiment support to new group leader
· Davide/Max/Gianluca: Arrange meeting with Paolo to discuss R1233ZE testing requirements before LS3
· Andrea: Update planning with ATLAS RPC Rack 61 dates; note ~8 weeks mechanical work, 2 people needed for at least 4 weeks
Gas systems 2026-10-15
Action Items
· Davide/Max: Investigate buffer pressure spike at 3:30 AM — determine if cause is chamber disconnection or other (e.g., CO2 composition effect).
· Davide/Louis-Philippe: Organize MFC swap from ALICE to RPC as soon as possible given ongoing chamber disconnections.
· Patrick: Prepare 2 slides on gas bottle registration procedure for next meeting.
· Team: Compile full bottle inventory and add entry for all purchased bottles to tracking system.
· Gianluca: Resume functional analysis for SciFi/NDT pump stop logic and confirm with experiment whether power-cut behavior is intended.
· David: Follow up on suspected purifier leak once unit is back in use (January).
· Team: Label all racks physically and retrofit existing racks with identifiers; update safety valve records with rack numbers.
· Team: Open/reopen ventilation ticket daily until resolved.
· LS3 planning: Begin ordering material for RPC; update planning table once delivery timeline is known.
Gas systems 2026-10-07
Action Items
· Max/Davide: Organize meeting with Paolo (Atlas muon coordinator) to escalate Nitrogen incident.
· Roberto: Send updated schedule reflecting holiday period (Jan 3–5 holidays, Jan 6–7 working days, Jan 7 = first Thursday).
· Patrick / Team: Assist with gas bottle registration and return. Prepare few slides with procedure
· Team: Compile full gas bottle inventory list for next week; identify bottles to return vs. keep.
Gas systems 2026-10-01
Action Items
· Gianluca: Verified buffer pressure alarm delay unit (5 seconds vs. 5 minutes) in recipe.-> there is an issue in the recipe -> checked again, it's in seconds (default 5 s)
· Patrick/Stefania/Gianluca: Clarify LHCb UT pipe/valve condition item; check functional analysis for manual stop behavior.
· NA62 Straw: Fabio available for up to two days; Roberto to confirm based on bottle availability.
Gas systems 2026-09-24
Action Items
· Gianluca: Investigate PLC logic for minimum valve opening threshold below 10%. CMS-RPC humidifier -> no values clipped in the PLC found
· Stefania (microcirculation): Order mechanical and electrical material; report estimated arrival at next meeting.
· Davide/Max/Gianluca: Check historical pump test record to identify which pump had the prior current absorption problem ATL-MDT. We tested VFD of pump 1 with pump 2 and it seemed ok: see https://eloggas.web.cern.ch/GASSYSOperationMaintenance/6610
Gas systems 2026 09 17
Action Items
· Davide/Max: Continue CO2 pressure-drop tests on Column B (Atlas-RPC) — check if drop rate decreases over repeated tests (saturation indicator). -> stable rate
· Davide: Perform full pump maintenance on all three RPC pumps (gasket material upgrade, needle valve replacement). -> done maintenance p2, non return completely broken. replaced. pump 2 still not ok after. Plan to replace all non-return -> something solved, but pump still not happy
Gas systems 2026-09-03
Action Items
Patrick/Gianluca: Investigate LHCb-UT, confirm correct logic and pipe (or valve or pneumatic pipes?) condition.- Andrea : finalize TID 904 and send link.
- Florian's mixer: Order required materials — planned for next week – who is ordering? Patrick for electrical
piquet:
LHCb pump filters to be changed or something (for LS3)-> TICKET
O2+H2O analyser to be checked -> TICKET
ATLAS-RPC rack 66 and 69 pressure alarm during purif 2 change over -> TICKET
NA62
glitch of CEDAR 6105, is it the keller? -> TICKET to check
ATLAS-TGC putifier Col B leak. loosing 1 bar in 1 day -> TICKET Davide check with Argon or CO2
CMS-DT pressure sensor PT1303 went to 0 for 20 minutes -> TICKET to follow Andrea
ATLAS-RPC purif -> affecting chamber pressure -> R66 check
12/2 ATL-RPC purif 1 some software issue and sms not indicating the right reason for the alarm -> TICKET
IR status, spares, .... --> TICKET
test binary gas analyser... -> TICKET
outcome of binary gas analyser test --> TICKET & buy a 2nd one --> Maria Cristina
DP pressure for pump filter in ALICE and LHCb -> TICKET -> @LPh + @Patrick [GASSYSTEMS-903] DP pressure for pump filter increasing - CERN Central Jira -> Stefania
chiller fluids to uniform between CMS, LHCb and ATLAS -> TICKET Maria Cristina
check if NV in purif is really useful --> TICKET
Calibration bottles O2-H2O status
ALICE
70 report from Anité [GASSYSTEMS-70] TPC gas quality - filters to Benoit - CERN Central Jira (I don't see the report, can you please add it?)
several alarms blocked: [GASSYSTEMS-628] ALICE alarms blocked - CERN Central Jira
TOF gas mixture analysis -> [GASSYSTEMS-639] TOF gas mixture analysis - CERN Central Jira & ELOG
TRD membrane is connected ? -> [GASSYSTEMS-717] TRD membrane status - CERN Central Jira
P&ID drawing check who is doing -> [GASSYSTEMS-736] ALICE P&ID drawing check - CERN Central Jira
MID swap of pumps during MD because sometime the system stop -> TICKET
ATLAS
MDT frequency converter (need to be replaced TICKET) ELOG - ATLAS MDT Test convertisseur 4101 avec la pompe 4201
RPC distribution rack regulation valve (TICKET)
RPC secondary mixer (TICKET), info to be given to ATLAS
RPC purif 3 circuit breakers & meeting -> [GASSYSTEMS-718] RPC purif 3 electrical issue - CERN Central Jira --> meeting when?
ATLAS-TGC flow difference --> [GASSYSTEMS-612] ATLAS-TGC flow difference - CERN Central Jira
CMS
RPC purif test at workshop, PLC needed -> TICKET
R134a insulation - isol'tut to check and see what to do -> ticket IO [GASSYSTEMS-578] R134a insulation - isol'tut to check and see what to do - CERN Central Jira
How much gas flow we need for the RPC purifier? --> [GASSYSTEMS-579] CMS-RPC How much gas flow we need for the RPC purifiers? - CERN Central Jira @MariaCristina notes to be added
RPC bypass pump too much closed --> [GASSYSTEMS-604] RPC bypass pump too much closed - CERN Central Jira
RPC with CO2 like ATLAS and effect on R134a recuperation -> [GASSYSTEMS-606] RPC with CO2 like ATLAS and effect on R134a recuperation - CERN Central Jira
R134a Upgrade (hardware and software) to be tested -> [GASSYSTEMS-594] R134a Upgrade (hardware and software) to be tested - CERN Central Jira
DT vaisala reading difference between SG and US -> [GASSYSTEMS-677] CMS DT vaisala reading difference between SG and US - CERN Central Jira
CMS-FGR -> TICKET should we add a module. Do we need to buy something? follow-up
CMS-FGR -> TICKET Maria Cristina già fatto per bypass
CMS-FGR -> TICKET flowmeter for Huber
CMS-RPC IR not stable -> elog Maria Cristina -> TICKET
CMS-ID flushing. refurbishing of old racks material and manpower need to be estimated -> TICKET @Gianluca ticket number for project
R134a huber temperature can be controlled by PLC -> TICKET
LHCb
TS1-> RICH1 leak search (postponed), SciFi some work from others expected
RICH1 what we learn from 1st fill -> [GASSYSTEMS-608] RICH1 what we learn from 1st fill - CERN Central Jira
summary of the C4F10 bottles --> TICKET or ELOG -> [GASSYSTEMS-660] summary of the C4F10 bottles - CERN Central Jira
alarms blocked: [GASSYSTEMS-631] LHCb alarms blocked - CERN Central Jira
RICH2 filter blocking -> [GASSYSTEMS-731] RICH2 pump filter differential pressure sensor not working - CERN Central Jira
P&ID drawing check who is doing -> [GASSYSTEMS-739] LHCb P&ID drawing check - CERN Central Jira
RICH1 cleaning , when? not before mid-september? -> TICKET
RICH1 remove membrane rack before end of HL-LHC operation and/or change piping-> TICKET
RICH2 injection through recuperated CF4 -> TICKET
fire detection alarms reported by Pieter, more info? but not on us. Cleaning of SG room -> TICKET
CODEX-b interlock for flammable gas detection -> Patrick
RICH1 leak repair -> December 9th tbc -> TICKET
NA62
CEDAR maintenance needed -> [GASSYSTEMS-609] CEDAR maintenance needed - CERN Central Jira
change of pressure sensor used for leak warning? -> [GASSYSTEMS-741] NA62-CEDAR move to keller pressure sensor? - CERN Central Jira
GIF++ TGC gas system and return flow: [GASSYSTEMS-624] GIF++ TGC gas system return flow - CERN Central Jira
[GASSYSTEMS-674] MFCs to be checked - CERN Central Jira :
- Fondoscala del MFC di R134A e sensore umidità del gas RPC [GASSYSTEMS-645] Fondoscala del MFC di R134A e sensore umidità del gas RPC - CERN Central Jira
- Neutrino platform gas analysis: [GASSYSTEMS-622] RE: Analisi di outgassing di diversi materiali - CERN Central Jira
- ALICE T10 MFCs: [GASSYSTEMS-669] ALICE T10 TR: calibration MFC pour C4F10 - CERN Central Jira
- ND280 MFCs to check [GASSYSTEMS-679] ND280 MFCs to check - CERN Central Jira
non-LHC safety valve --> check lista di Fabio
[GASSYSTEMS-172] non-LHC safety valves to be verified - CERN Central Jira
ELOG - safety valves to be verified for non-LHC systems
Additional requests/projects/discussions
887 CEDAR new "mixers" --> [GASSYSTEMS-509] CEDAR for beam lines - CERN Central Jira
AMBER
EDMS leak test?
test certificate x-ray?
ATEX certificate?
who is technical coordinator
resource manager Oleg D?
no money? should we stop? and resume in 2026?
Commissioning when? -> TICKET
when they would like to start? Moritz? -> ask
LEAK DETECTORS LIST -> TICKET
MAINTENANCE INTERVENTIONS WORK ORDER FOR STATISTICS -> TICKET
PROJECT 2025
summary TICKET
examples of topics for the common discussions:
-cms id flushing -> Andrea
-cms r134a operation and spare -> Andrea
-cms cf4 operation and spare -> Andrea
-atl tgc nc5h12 -> Kacper
-Analysis boxes -> LPh
-C4F10 new recuperation installation -> Patrick
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