From Hardware Commissioning to Machine Check-out S Baird LHC HC review 11-13 May 2005
Questions…. • How does HC leave a sector? • Which cycles, to what energy…? • Ready for beam? • Late/repaired systems? • What happens to a sector after HC and before beam • Which systems will be maintained? By whom? • Who is responsible for coordinating interventions/repairs? • Re-testing/re-commissioning • What does OP expect? • Safety issues • Conclusions…
How does HC leave a sector? • Sectors will be commissioned to nominal and no higher. I.e. 7 TeV • Maybe lower… If there is a weak magnet • After HC a sector is “ready for beam” • Sector run has been through all standard LHC operations • First 4 sectors will NOT be kept cold. They will “float” • Lack of resources (Cryo) • 400 kCHf/month to keep a sector at operating temperature • RF does not want to warm up point 4 after HC… • Do RF commissioning as late as possible??
What happens after HC? • HC will not wait for late but non-essential equipment • E.g Collimators, BLM,s • Late installation done by specialists – coordinated by HC team • This may need support from vacuum, cryo… & others • Repairs • Done by specialists – coordinated by HC team • Again possible need support from vacuum, cryo… & others • Strong need for coordination with on-going installation & HC
Vacuum & Cryo support • Cryo will have a small team to cover work in the already commissioned sectors • With at least one responsible person/point • Vacuum will also have people responsible for installed/commissioned sectors • Vacuum operation/maintenance will start before first beam • Two Vacuum teams (CERN staff), who will not be “fully loaded”, will be available for interventions on commissioned sectors • These teams will make all non-standard interventions • However, late installation and equipment changes should not be programmed in parallel with sector “re-commissioning”
What happens after HC? • Need a solid co-ordination of all post-HC installation and repairs • Using same resources as HC • Restarting/re-testing all systems will also need solid co-ordination • But “HC circus can only perform at one pit at a time” • Restarting/re-testing looks like the end of a shutdown • Early role for a shutdown co-ordinator
Sector re-commissioning • (Re)cool-down - main roles for Vacuum & Cryo • Vacuum need 2 weeks per octant before (re)cool-down can start • Vacuum only has resources for 1 octant at a time • Cryo need 6 weeks per octant for first (re)cool-down • Nominally 3 weeks but this is the “first time” • Cryo can work on octants in parallel • Therefore (re)cooling of 4 octants needs a minimum of 14 weeks • During last 4 months absolutely no vacuum work elsewhere (including injectors)
Sector re-commissioning • Some systems may need a full re-commissioning if there have been changes or repairs • Safety systems, machine/magnet protection etc. • PIC, WIC, QPS etc. will need some sort retesting in any case • This re-commissioning will be part of the HC but it looks like a restart (hardware tests leading into cold check out) after a shutdown
Sector re-commissioning • For existing machines • Hardware tests coordinated (with a daily meeting for planning and decisions etc) by Shutdown Coordinator working very closely with by OP • Hardware tests stop and lead into the machine cold check out under OP responsibility • HC responsible for cool-down and retesting PIC, WIC, QPS etc… • As soon as a sector is cold and ready hand over to OP • Switch on done by system specialists (RF, BT, BDI, CO, PO etc…
What does OP expect? • All systems fully tested to nominal (plus X%?) • All systems put through all “standard” LHC cycles • All safety and machine protection systems operational • Sector ready for cool-down or already cold? • Get hands-on experience as soon as possible
Safety issues • LHC tunnel is a single worksite • TS & SC established procedures for HC. • SC recommend maintaining this responsibility for late installation/repairs • E.g exchange a magnet • Use same procedures safety procedures as installation • Need cryogenics, vacuum as well as system experts • When should HC team officially hand over to OP? • Safety-wise prefer not to sub-divide the tunnel into separated work-sites as this requires a physical separation – leads to a single hand-over • Not ideal….
Conclusions… • LHC will be tested to nominal performance and not beyond • LHC may be tested to less than nominal performance if there are “weaker” elements • HC team should be responsible for sectors until they are cold and ready to start hardware switch on for machine check-out • OP should coordinate this switch on ready for the full machine check out and getting the LHC ready for beam
Conclusions… • Sector re-commissioning, late installation and system repairs look rather like shutdown work • Appoint a shutdown coordinator (part of the HC team?) as early as possible to coordinate these activities with a strong OP involvement • OP should take responsibility for retested sectors as they become available to start machine check out • Coordinate these handovers with the testing/certification of the access safety systems