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Comprehensive testing of the Large Hadron Collider's access system, including patrolling, beam mode simulations, and access delegation operations. Organized by a large team in collaboration with AB/OP for efficient operation. Test results analyzed for enhanced safety and functionality.
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Global Tests of the LHC Access systemOutcome P. Ninin, T. Petterson, S Grau, T. Ladzinski 18th January 2008
Global tests • Organization: • Organized by Silvia Grau and Pierre Ninin • Performed by a large team of TS/ASE • In excellent collaboration with AB/OP (to help searching LHC, giving access, driving EIS-beam equipment, etc…) • From Monday 7th to Sunday 13th January
Main Test Objectives • Test the Access System when doing a patrol of all the LHC points • In « Access Mode », test the correct system behaviour when one or more EIS-beam becomes unsafe • In « Beam Mode », test the triggering of all the « EIS-BEAM» and external interfaces (BI, LBDS) in case of intrusion, door opening inside the LHC or Emergency stop. • Test the access delegation operation with the Experiments • In collaboration with AB/OP, prepare the LHC Access operation and train the users
Test Strategy Step 1: Factory acceptance Step 2: Site acceptance LHC1 Step 3: Global acceptance LHC1.8 LHC2 LHC5 LHC6 LHC3 LHC4 LHC4 LHC5 LHC7 LHC6 LHC3 LHC7 LHC8 LHC8 LHC2 LHC1.8 LHC1
Monday 7th – Sunday 13th January • Monday: • Move the system from “installation” to “operation” • Tuesday to Thursday: • Patrol the LHC • Thursday evening • Closing the LHC and move to BEAM mode • Friday • System test in Access mode • Saturday: • System test in Beam mode • Sunday: • Move the system back to “installation” mode
Patrolling the LHC • Simplified quick patrol of the 160 access sectors : • All patrol boxes have been rearmed and sectors quickly searched. • Seal (“Plombage”): • Emergency exit handles on all doors and access points • Teach the people to open doors the normal way • Emergency opening with the “emergency handle” is of course still possible • After the tests, the seals have been left on most doors • Patrol procedure • AB patrol procedure not used with the exception of LHC8 • ATLAS real patrol procedure done (without SSA) • CMS patrol procedure attempt
Patrolling the LHC • Some people had to work in the sectors being searched: • List of authorised workers was provided before the tests • Workers were ready with the “biometry” and the dosimeter, no particular problem reported to access LHC in general mode • Access given to workers in restricted mode in the patrolled area • Access to experiments allowed throughout the whole week: • Grids removed at PX24 and ULX15 access points to allow access to ALICE and ATLAS during the tests. • One guardian was placed next to each missing grid to control access • Only one door forced between the ATLAS cavern and the service area (which had to be re-patrolled) • Atlas suspended work Saturday, due to the almost permanent BIW signals resonating…. • Alice representative in CCC during the tests to inform the experiment in case of real “evacuation”
Tests in access mode • “One or more EIS-beam becomes unsafe” • Initial state: • LHC fully searched, • “Access mode” • All EIS-beam are safe Eis-beam: Power converters: LHC 2,3,7,8 18kV & 400V cells: LHC 2,3,7,8 TEDs: TI2 & TI8 Access Safety Blocks: LHC 3 External interfaces Beam Imminent Warning LHC beam dump Beam interlock system SSA SPS access system
Tests in access mode • Test case A: One EIS-beam becomes unsafe: • Result: • the system goes to access-off • Test case B: Two EIS-beam become unsafe: • Result: • the system goes to access-off • and BIW (Beam Imminent Warning) sirens start • Systematic tests done, for each EIS-beam, one by one • Tests were successful. • Remarks: • First time LHC went to “access-off”, after BIW : • evacuation siren in point 6, fire alarm and ODH alarms in point 6, and 3 minutes later AUG in point 8. • All false alarms, but resulting in two fire-brigade interventions.
Tests in beam mode • Test case: Move into « safe position » all « EIS-Beam» and external systems (BI, LBDS) in case of: • Intrusion, • Door opening inside the LHC • Emergency stop. • Initial state: • LHC fully searched and closed (leaving some people in, on purpose, for the tests) • “beam mode” • EIS-beam unsafe (18 KV cells “ON”, power converters “ON”, TEDs “OUT”, etc…) • A sample of all types of doors tested all around the LHC: • inter-site doors, sector doors, end of zone doors, trapdoors, ventilation doors, access point (both PAD and MAD), etc… • One real AUG done in LHC 7: OK • Outcome: Tests successful • All intrusions detected • Interlocks triggered all the EIS-Beam to move into SAFE position
EIS-Beam and external interfaces • Beam Imminent Warning when two “EIS-Beam” go unsafe: should actually be “Evacuation siren” rather than BIW • A power converter and its associated power distribution cell are currently considered as two independent EIS-Beams: should be considered as a single one • On several occasions the TEDs could not be moved. Still unclear why. • On several occasions: LASS saw TEDTI8 “OUT” (actually “not IN”) although it was “IN”. Position Sensor issue? • Electrical problems with two power converters (warm magnets in point 3 and 7) – under investigation • LBDS: triggered as foreseen, timing of signals to be investigated • BIS: final system not installed
Test Results • Access system installation was completed just before Christmas • Project team is satisfied of the test outcome • 6 days extensive use of LASS and LACS • All LASS and LACS functionalities tested • Many lessons learned • Post-mortem data analysis still ongoing • Not easy due to the multiple data sources • Some external systems not in final configuration • Test of the interfaces (LBDS, PC, BIC,…) but not of the complete chain
LHC ACCESS CONTROL SYSTEM - LACS • Improvements seen in software since the LHC7 and LHC8 (TI8 test) summer tests: • Human interface to LACS works fine but should be improved (slow response, could be more human friendly, occasional restart of the application) • IHM Lass data representation to be controlled • Video matrix migrated to a dedicated PC • System diagnostics still have to be improved • Token distributor issue: • problem under investigation: • Either common mode in key distributor • or evolution not in phase between HW & SW • Contractors and supplier contacted • Some minor non-conformities to be fixed • Mechanical : equipment mounting (locks), PAD fine tuning… • Information stickers • Access point software • User information and local IHM to be improved
LHC ACCESS SAFETY SYSTEM • The LHC Access Safety System behaves as specified • A few relays had to be changed, a few problems solved on line • Diagnostic module and interface with TI still to be developed • Homogenization to be done between the LASS software installed for TI8 test (LHC7 & 8) in November 06 and the version deployed on the other LHC sites (LASS V.2)
Next stages • LASS • Once the key distributor issue is corrected, the LASS can be used as it stands today to ensure the safety of the personnel in the LHC. • Preparation of version 2 including all modifications/upgrades • required by AB/OP (patrol behaviour, evacuation instead of BIW in case of two EIS beam are Unsafe…) • Sectorization changes (new doors…) • Minor software upgrades • Ideally before the LHC start-up • Expect 6 months of development and testing of new software version • On site • Personnel permeability of the 160 access sectors – i.e. closing the small loopholes still open. • To be followed up by DSO and OP acceptance tests
Other lessons learned • Training for using the access system • All users : film prepared, soon integrated in the CERN training • Firemen : • How to enter the machine without loosing the patrol - procedures, training and keys… • Inform firemen before and during the tests
To be done • Test specific TI8 loop as done for LHC2 • Test delegation operation by the experiments • Test all the fire doors and crinolines when installed • Install Material Access Device personnel detection • Interface with the Atlas Safety System.
Magali’s conclusion (AB/OP) • Excellent collaboration between TS and AB • Overall a very successful and interesting week • To be followed up by DSO and OP acceptance tests