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Testing of LHC Magnets in Cryogenic Conditions: Operational Challenges, Status & Outlook. V. Chohan SM18 Operation CERN. Talk Outline. The Environment Operational Challenges Throughput Strategies Accomplishments Outlook Conclusion. The Environment.
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Testing of LHC Magnets in Cryogenic Conditions: Operational Challenges, Status & Outlook V. Chohan SM18 Operation CERN
Talk Outline • The Environment • Operational Challenges • Throughput Strategies • Accomplishments • Outlook • Conclusion Particle Accelerator Conference, 16-20 May 2005, Knoxville, Tennessee, USA.
Work Environment: Operational Challenges • Resources • 12 Test Benches arranged in pairs so, 6 clusters( A to F) • Water for 4 magnet powering at the same time, • Cryogenics capacity and limits have improved in 2005, but still it has its constraints in warming, cooling and the number of quenches permitted in real time, • Operation staff consists of 7 CERN staff (up to end 2004) on loan from CERN Accelerator Operation & 15-20 persons on exact 1 year contracts from India & constantly rotating. • All these conditions pose formidable challenges to set up and run operation Particle Accelerator Conference, 16-20 May 2005, Knoxville, Tennessee, USA.
Throughput Strategies • To Achieve the project objectives it was necessary to : • Plan and schedule tests • A “To Do List” was formulated which enumerated the minimum tests to be conducted in the magnet • Collate results & Tests summaries and Track the progress of tests • A web based tool SM 18 Tests Management Scheme (SMTMS) was developed Particle Accelerator Conference, 16-20 May 2005, Knoxville, Tennessee, USA.
Throughput Strategies • Develop tools to aid the operation Team • Integrated resource monitoring displays were generated • Electronic Traveller was developed (All actors) Particle Accelerator Conference, 16-20 May 2005, Knoxville, Tennessee, USA.
Results till end-April 2005 Particle Accelerator Conference, 16-20 May 2005, Knoxville, Tennessee, USA.
Cumulative Total: All Magnets (includingRepeats & Rejects) Particle Accelerator Conference, 16-20 May 2005, Knoxville, Tennessee, USA.
Countdown LHC : Simple Magnets Count Basis • In 2004 we achieved a magnet tests rate of ~ 55 Magnets • We need to go up to ~ 69 magnets per month to complete the magnet tests byNovember 06 • This figure assumes ~ 1900 magnets tests i.e, ( 1706 + ~ 11 %) where11 %is the number ofretests. 2004 Particle Accelerator Conference, 16-20 May 2005, Knoxville, Tennessee, USA.
Countdown LHC : Simple Magnets Count Basis • To achieve the targetof 69 magnet tests per month, a course of action is underway since Feb 2005. • Results from early 2005 shows a positive trend. Particle Accelerator Conference, 16-20 May 2005, Knoxville, Tennessee, USA.
Conclusions Despite, • CERN’s financial constraints in 2000 and change in strategy, • late delivery of tests benches and related equipment, and • certain under capacity in cryogenics till last year, the magnet testing programme is now fully on schedule to meet the project deadlines. Particle Accelerator Conference, 16-20 May 2005, Knoxville, Tennessee, USA.
Extra Slides Particle Accelerator Conference, 16-20 May 2005, Knoxville, Tennessee, USA.
Magnet Statistics until April 05 Particle Accelerator Conference, 16-20 May 2005, Knoxville, Tennessee, USA.
How do we accelerate the testing of magnets ? Our most precious resource is the bench occupancy time hence, one must “Reduce the bench occupancy time” • The bench occupancy time consists of • Connect Time : Connection of Magnet to the CFB • Cooling Time : Cooling the Magnet to 1.9 K • Cold Test Time : Training the Magnet + Special Measurements • Warming Time : Warming the Magnet to 300 K • Disconnect Time : Disconnection of Magnet from the CFB (For a Dipole, this total should be theoretically 108 hrs.of which cold test time is 36 hrs. ) • To reduce the bench occupancy time,any OR all these times must be reduced Particle Accelerator Conference, 16-20 May 2005, Knoxville, Tennessee, USA.
Bench Occupancy Reduction Schemes • Enhanced Cryo-Capacity in 2005 & resulting optimism • Moderate Proposals(Presented at MTM Review Jan 05) • Fewer Single Stretch Wire Measurements for Arc-SSS magnets • Reduced Training Quenches beyond 7 TeV: 3 Quench Rule • Improved Production Control at warm : Diode Tests • Reduced duplication : WP04 Insulation Tests • Additional [Radical] Proposals that could still be done • Schemes that curtail training to currents upto 11 kA (~ 6.5 TeV operation) ; implies ‘training’ in the tunnel to go up in Energy • Reduce “ Connect Time” by not doing certain tests at warm on the bench Particle Accelerator Conference, 16-20 May 2005, Knoxville, Tennessee, USA.
Cryo-Capacity 2004 & Estimates 2005 • The Average Wait+Coolingtime was 45 hours & Wait+Warmingtime was 20 hours • We are told to expect a gain of 50 % in CWS unit of cryogenics in 2005. so at least 1 more magnet in 300K-90K or 30K-300K phase • Wepredicta Wait+Cooling time of ~ 30 hours & Wait+Warming time of ~15 hours Particle Accelerator Conference, 16-20 May 2005, Knoxville, Tennessee, USA.
Cryo-Capacity so far in 2005… • In 2004 The Avrg Wait+Cooling was 45 hours & Wait+Warmingtime was 20 hours • We were told to expect a gain of 50 % in CWS unit of cryogenics in 2005. so at least 1 more magnet in 300K-90K or 30K-300K phase • Wepredicta Wait+Cooling time of ~ 30 hours & Wait+Warming time of ~15 hours Particle Accelerator Conference, 16-20 May 2005, Knoxville, Tennessee, USA.
SUMMARY: Time Saving Schemes • Based on Moderate Proposals & Cryo improvements Cold Test times include Magnetic Measurements (Special & Non special) Particle Accelerator Conference, 16-20 May 2005, Knoxville, Tennessee, USA.
Projections: Accelerated Rate for Dipoles & ARC SSS & Optimistic Rate for IR SSS Particle Accelerator Conference, 16-20 May 2005, Knoxville, Tennessee, USA.
Assumptions • All the moderate proposals mentioned would be implemented • It is assumed that a figure of 1869 magnets will have to be tested including retests. Retest rates: 11% dipoles, 6% Arc SSS, 6%IR SSS • It assumed that the magnets will be available for testing as and when desired Particle Accelerator Conference, 16-20 May 2005, Knoxville, Tennessee, USA.
Projections: Accelerated Rate for Dipoles & ARC SSS & Optimistic Rate for IR SSS • Highlights: • Testing Time for Dipolesis ~113 hrs • Testing Time for ArcSSSis ~ 137 hrs • Testing Time for IR- SSS ~ 168 hrs? • Completion of testing of all MAGNETS • Dec 06 • Assumption: • We can attain a figure of up to 69magnets per month Particle Accelerator Conference, 16-20 May 2005, Knoxville, Tennessee, USA.
Projections: With ~ 62 to 65 Magnets per month Particle Accelerator Conference, 16-20 May 2005, Knoxville, Tennessee, USA.
Projections: With ~ 62 to 65 Magnets per month • Highlights: • Testing Time for Dipolesis ~116 hrs • Testing Time for ArcSSSis ~ 170 hrs • Testing Time for IR- SSS ~ 240 hrs ? • Completion of testing of all MAGNETS • March 07 • Assumption: • We can attain a figure of up to 65magnets per month Particle Accelerator Conference, 16-20 May 2005, Knoxville, Tennessee, USA.
Ramp 1 [To 12850A] Rules : 15 April 04 Quench? magnet trained! Yes Iq>12kA No Generate .u file at 12850A & SPA Yes Iq<12kA MM*, PT8, CDAP Ramp 2 [To 12850A] Min. NRJ at 11.85 kA Yes Iq>12kA Quench? Ramp 2 [To 12850A] No MM*,CDAP Yes Iq<12kA Quench? Generate .u file at 12850A & SPA Train to 12850A (see rules) # 8 ramps Yes Yes If shafts? No No No PT8 Yes MM*, PT8, CDAP Ramp 9 [To 12850A] Min. NRJ at 11.85 kA Yes Quench? CDAP CDAP at 4K No Generate .u file at 12850A & SPA Generate .u file at 12850A & SPA Warm-up on 10th Quench at 4K (SSL) MM*,CDAP MM*,CDAP Min. NRJ at 11.85 kA Min. NRJ at 11.85 kA Warm-Up
MM* If Shafts Are Present! PT8 = Ramp to 12 kA & SPA CDAP =HV@ cold Final Min NRJ = Quench provoked FPA Disabled • # Max 9 Ramps to 12850A; If this terminated in <= 9 ramps • Then follow flowchart , else: • magnet is poor & do warmup on 10th with 4K quench • Instead of PT10 • THEN: Thermal Cycle if AntiC exist & so put in shafts • ELSE(( if no AntiC) – Magnet removed & Standby Thermal Cycle Rules with Shafts Inserted : In the 2nd Run: if 1st Q above (8.4 T) 12000A then MB accepted if 2st Q above (8.6 T) 12350A then MB accepted ELSE MAGNET REJECTED WITH poor perf non-conformity but with the rules : if Quenches are localised only in 2nd run (with shafts inserted only in the 2nd run ): perform 5 quenches only And END the Tests . if Quenches were localised in first RUN : then perform max 2 localized quenches only in 2nd run Particle Accelerator Conference, 16-20 May 2005, Knoxville, Tennessee, USA.
Additional Tools • To improve operational efficiency and smoothen work flow, operational tools were designed and implemented. • Many innovative ideas and proposals emerged with discussion held with operation group. • Some tools were developed by ingenious personnel of SM 18 operation team. • SM 18 Test Master System, • E-Traveller, • Integrated Resource Display. Particle Accelerator Conference, 16-20 May 2005, Knoxville, Tennessee, USA.
Additional Tools: SMTMS • Description • The SM 18 tests management system (SMTMS) was developed which uses the CERN backbone in web based services and features of Access data base. • Uses • Automatic generation of Tests sequence and reports, hence reduced the ‘bureaucratic’ activity of typing 11 reports after the tests were conducted on a magnet • Track the progress & Statistical data of tests were important spin-offs of this tool. Particle Accelerator Conference, 16-20 May 2005, Knoxville, Tennessee, USA.
Additional Tools: E-traveller • Requirement • With 12 benches in operation, the tests scenario in SM 18 is very dynamic. • Description • The E-traveller is a software toolinterfaced to mobile phones that alert the various teams of their need on a particular magnet. • Advantages • Time to locate members of other teams is reduced. • Reduced verbal communications between teams (Indian personnel have limited knowledge of French ). Particle Accelerator Conference, 16-20 May 2005, Knoxville, Tennessee, USA.
Power Cryo Water Additional Tools : Integrated Resource Display • Requirement • Resources such as Cryo Capacity,power, water are limited. The electronics too is common between benches in a cluster • The operation team has to juggle with the resources to carry out tests. • Description This integrated resource display was generated by interacting with software programmes controlling the resources and running under various operating systems. • Utility This enable the operations crew to optimise resources usage and prevent resource conflicts from arising. Particle Accelerator Conference, 16-20 May 2005, Knoxville, Tennessee, USA.