LHC Magnet Tests:

1. LHC Magnet Tests: A challenge for an Operation Team Always set the trail, never follow the path V. Chohan G.H. Hemelsoet Cern Geneva

2. Outline • Introduction to SM18 & Magnets Tests Facility • Operational Techniques • The Challenge • The Actors • Some tools set up by operation • Web servers • Magnet Training Criteria • Priority Handling • Online and Real Time reports • Conclusions

3. SM18 Tests • Limited Infrastructure • Heterogeneous Team • Staff and outside contractors • Core of test manpower was a collaboration from India • Tight schedule to test 1706 magnets • In fact more than 1900 tests (with spares and repeats)

4. Magnets tested 1919 Magnets tested on time

5. Cumulative tested magnets Early Performance With Operational Techniques

6. Staffing: Various Team of SM18 Mainly associates from DAE India Equipment support Industrial Consortia

7. Warm –up Magnet Tests.. What do we do ? New magnet arrives.. Insulation test, connection to CFB Preparatory tests (functioning of protection systems & instrumentation, insulation…) Cool down to 1.9K Preparatory tests (tuning DAQ..) Insulation tests Functioning of protection systems Power tests (&Training) Magnetic measurements Final insulation tests @cold Final warm tests Electrical integrity Resistance measurements.. Final insulation tests Disconnection from CFB

8. C2 F2 C1 F1 B2 E2 B1 E1 A2 D2 A1 D1 Test Facility in SM18 • 12 test benches in SM18 • Roughly speaking: • 3 magnets @1.9 ‘k • 3 in warm-up or cool-down phase • 3 in connection or disconnection phase • 3 spare &/or dedicated to special use • 6 power supplies ( 1 per 2 benches) • Dipoles as well as SSS’s Testing

9. Web Server (SMTMS) • Maintains electronic repository of tests results • Links tests results with management tools • Tracks test progress & test statistics • Automatic generation of test reports • Automatic filling of the tests done

10. E-Traveller • Web based tool with mobile phone interface and video display – alert teams • Keeps track of electronic, signature based information exchange • Automatic time stamped log of tests activities • Minimizes verbal communication..

11. Real Time Information • Real time status of the facility was displayed on the web and on TV screens around the CERN LHC Dashboard

12. Training Rules • Earlier, all magnets were trained to ultimate field (12850A ~9T) • 3-4 hours recovery time between quenches, Time consuming… • But… Most of the ‘good magnets’ cross nominal field (11850A ~ 8.33T) in the second training ramp.. • [ year 2003 Observation by OP Team] • Two-Quench Rule: Accept the magnet if it crosses nominal field in Second training with small margin! • Three-Quench Rule: Accept the magnet if it crosses 12250 A (~8.66 T) in third training, even if it had not passed the preceding rule.. 80% magnets cross nominal in 2nd ramp!

13. Magnet Appraisal & Performance Sheet (MAPS) • Single page report on rule based magnet goodness evaluation • OP Team empowerment for rapid, round the clock decision taking on first level of goodness evaluation • Mitigates issues of magnet storage logistics

14. Overall & Cryo Priority Setting • Ensure that magnets follow the desired cryogenic phase distribution, within the limits of possibilities due to the varying training performance ( a priori not known)

15. Rapid On Bench Thermal Cycle(ROBTC) • Earlier, ‘poor magnets’ were disconnected from bench, fitted with anticryostats, tested again at a later date… • Additional disconnection, connection, preparatory tests… time consuming.. • But.. Quench performance improves after thermal cycle • Rapid On-Bench Thermal Cycle (ROBTC): Rapid thermal cycle of a poor magnet without disconnection from test bench

16. Prototype facility Try to push every magnet at the limit Repair or improve as they have time Operation not actively involved in Software and design of facility Each group has its own idea and implements its way Culture of keeping control and hiding things Running accelerator Try to push the whole complex at the limit Fast and coordinated repair and improvement Operation is central about design and software development Advice of operation before implementation Open environment with trust of operation Prototype vs Operation

17. Before 2002 All problems treated the same way No clear distinction between magnet problem and equipment problem Poor global view Each magnet has its own Excel files with redundant information After 2003 Separation for magnet and bench problems E-log book for Equipment Database for magnets Global web generated view One data base for all magnet information and an automatically generated Magnet and Test Result paper logbook. Operation know-how

18. Conclusions • The tools developed by Operation helped a lot to finish the magnet tests on time • Identify bottlenecks • To do list • Statistics • Real push from the team to gain time • Change of the rules • Tracking of down time • Real time Management of the facility • Priorities • Web Display Whether we play a large or small role, by working together we achieve our objectives.

19. Foreseen Times • Standard time • 12 hrs connection • 12 hours vacuum pumping • 26 hours cooldown • 36 hours cold test • 12 hours warm up • 12 hours disconnection • Total 108 hours per magnet • (4.5 days of 24 hours)

20. Ideal situation • To ensure a maximal usage of the facility, a cog-wheeling strategy has to be set up.

21. In Reality …

22. SM 18 Hall SM 18 control Room Status Offices Web Server Operational Techniques • Web based database • SM18 Test Management System (SMTMS) • Links electronic repository of tests results with other management tools • Provide real time view of the facility to identify bottlenecks • E-traveller • Web based, electronic signature based information exchange tool

23. Operational Techniques • Improved Training rules • Use the last quench of a magnet to help the warming up • Modified Magnet Training Criteria • Two-Quench Rule • Three Quench Rule • Rapid On-Bench Thermal Cycle (ROBTC) • Thermal cycle of a poor magnet without disconnection from test bench • Time & space optimization • Overall & Cryo priority handling • 24 hour priority decision by OP team for effective & clash-free utilization of ALL resources ( Cryo, Power, bench etc) • MAPS • Single page record of ‘rule based magnet goodness evaluation’