LHC Magnets: Cold Tests & Throughput V. Chohan SM 18 Operation CERN

V. Chohan LHC Project Workshop-Chamonix XIV, Jan Talk Outline The Environment –SM18 Operation –Boundary Conditions Current Situation –Results to Date –Summary Outlook –Projections –Concerns & Worries (No Elaborate Status Report & Facts from the floor level !!!)

The Environment

V. Chohan LHC Project Workshop-Chamonix XIV, Jan SM18 Magnet Tests : What it’s all about Demands on SM18 Operation Project Management Magnet Production LHC Beam Running in & Minimum dI, dE provision Accelerator Physicists

V. Chohan LHC Project Workshop-Chamonix XIV, Jan Work Environment Fixed 12 Test Benches arranged in pairs so, 6 clusters( A to F) 6 Main Power Converters 6 sets of Electronics for testing 1 per cluster Mobile For Q-location & MM we need to install Special 15 m Shafts Shafts require Anticryostat mounting in magnets Mobile Racks for HV insulation tests & Magnetic Measurements Utilities Water for 4 magnet powering at the same time Cryogenics capacity and limits Manpower [ 24 hr Tests Operation Staff special arrangements] 7 CERN staff (up to end 2004) on loan from CERN Accelerator Operation persons on exact 1 year contracts from India & constantly rotating Cryogenic Support staff ( 3 per shift) from Industrial Support contract ICS “Magnet connectors” working 24 hours since June 2004, but not ROCLA operators Support Generalized Equipment support as opposed to specialized support as found in 24 Hr. OPERATION in CERN & “physics” is not at stake if specialist ‘fixing’ is delayed

V. Chohan LHC Project Workshop-Chamonix XIV, Jan Utilities : Cryogenics Capacity Cryogenics capacity (in 2004) and limits :  3 to 5 1.9K and under cold tests,  1 magnet in 300K to 90 K phase,  1 magnet in Last (Warm up) Quench to 300K phase,  1 magnet in 90K to 1.9 K phase with a further capacity constraint of not exceeding 9 recoveries of high field quenches or initial cooling from 4.2 K to 1.9 K per 24 h We need to ensure that the magnets under the tests programme follow the cryogenic phase distribution as above, within the limits of possibilities due to the varying training performance ( a priori not known) and respecting all the other environment constraints mentioned earlier

Current Situation

V. Chohan LHC Project Workshop-Chamonix XIV, Jan Magnets Tested: 2004 A total of 396 Dipole & 55 SSS magnets were tested during the year 2004, these also include repeat magnets & IR-SSS. An estimate of 45 Dipole & 10 SSS magnets per month could be expected during year 2005, with the present environmental / test conditions

V. Chohan LHC Project Workshop-Chamonix XIV, Jan Results to Date DipolesDipoles Repeated Arc-SSSArc-SSS Repeated IR-SSS Year Not Applicable 2 Year (about 11%) 4933 TOTAL Includes Rejects & Repeats 55 Includes Rejects & Repeats Cumulative Total 49157

V. Chohan LHC Project Workshop-Chamonix XIV, Jan Cumulative Total: All Magnets (including Repeats & Rejects)

Outlook

V. Chohan LHC Project Workshop-Chamonix XIV, Jan Countdown LHC : Simple Magnets Count Basis We are at the rate of ~ 55 Magnets tested per month (sustainable) The testing would end in April 07 We need to go up to ~ 62 magnets per month. In this case, The testing would end in January 07 It all depends on many factors but principally for the sake of this simple calculation, one needs to consider what % of magnets get repeated & so forth leading to raw testing figure of : ( x %) The cut-off around 1893 as an example assumes x =11 % in this Figure

V. Chohan LHC Project Workshop-Chamonix XIV, Jan Target 2007 : Simple Magnets Count Basis It would be judicious to achieve a figure of ~ 69 magnets per month to finish by Nov 2006 This rate of testing is desired to realise the objective of “First LHC Collisions by Summer 2007” & Provide for contingencies

V. Chohan LHC Project Workshop-Chamonix XIV, Jan 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

V. Chohan LHC Project Workshop-Chamonix XIV, Jan 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

V. Chohan LHC Project Workshop-Chamonix XIV, Jan Cryo-Capacity 2004 & Estimates 2005 The Average Wait+Cooling time was 45 hours & Wait+Warming time was 20 hours We are told to expect a gain of 50 % in CWS unit of cryogenics in so at least 1 more magnet in 300K-90K or 30K-300K phase We predict a Wait+Cooling time of ~ 30 hours & Wait+Warming time of ~15 hours

V. Chohan LHC Project Workshop-Chamonix XIV, Jan SUMMARY: Time Saving Schemes Average Time to Test magnets (hrs) DetailsDipolesArc-SSS PresentFuturePresentFuture Connect Time Wait +Cooling Time Cold Test Time Warming Time Disconnect Time8888 Total test Time Based on Moderate Proposals & Cryo improvements Cold Test times include Magnetic Measurements (Special & Non special)

V. Chohan LHC Project Workshop-Chamonix XIV, Jan The gains only refer to Dipoles & Arc-SSS because we have No Experience with IR-SSS The calculation leads to 52 Dipoles & 16 Arc-SSS & i.e., 68 magnets could be tested per month, in a bench configuration of 8 Dipole +3 Arc SSS and leaving 1 Bench for IR-SSS However as it is obvious from above, the completion date cannot be based on a simple number count basis. The matter becomes much more complicated due to our boundary conditions…..throughput of Dipoles & Arc-SSS, matched bench allocation etc.. An appropriate method to evaluate the projection date must take into account that the LHC ring is made up of different types of magnets which require appropriate bench mechanical & electrical configurations for testing –1232 Dipole Magnets –360 ARC SSS Magnets –82IR SSS Magnets (DS + MS Type) –32IR SSS Magnets (DS_MQ Type) 1706 Total number of Magnets Summary : Time Saved per magnet

V. Chohan LHC Project Workshop-Chamonix XIV, Jan Projections : Accelerated Rate for Dipoles & ARC SSS & Optimistic Rate for IR SSS

V. Chohan LHC Project Workshop-Chamonix XIV, Jan 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

V. Chohan LHC Project Workshop-Chamonix XIV, Jan Projections : Accelerated Rate for Dipoles & ARC SSS & Optimistic Rate for IR SSS Highlights: Testing Time for Dipoles is ~113 hrs Testing Time for ArcSSS is ~ 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 69 magnets per month

V. Chohan LHC Project Workshop-Chamonix XIV, Jan Projections : With ~ 62 to 65 Magnets per month

V. Chohan LHC Project Workshop-Chamonix XIV, Jan Projections : With ~ 62 to 65 Magnets per month Highlights: Testing Time for Dipoles is ~116 hrs Testing Time for ArcSSS is ~ 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 65 magnets per month

Concerns & Worries

V. Chohan LHC Project Workshop-Chamonix XIV, Jan Possible Concerns & Worries for installation 1.IR-SSS –Testing : The testing of Insertion Region SSS is an uncharted territory to date and we need to ensure we have sufficient time for these within the existing boundary conditions. From our present limited experience, it takes a up to a 1 week to modify the bench to permit IR-SSS mechanical & electrical connections. 82 IR SSS are individually powered so one needs to provide at least the transfer function for powering & machine energy correlation even if detailed magnetic measurements are not done IR-SSS also need special Magnetic test cycles Logistics, Transport (avoid all issues that plagued Arc SSS in 2004) –“OFF-THE-SHELF” Availability for installation ?

V. Chohan LHC Project Workshop-Chamonix XIV, Jan Possible Concerns & Worries 2. Manpower & Continuity –Indian Associates With fixed one year contracts, there is continuous rotation of people, hence some are always on the learning curve. This could be a problem in an accelerated magnet testing scenario which requires continuity & stability. –CERN AB-OP Staff In case of 2006 early Accelerators start-up how would the SM18 Operation cope with reduced Stable CERN support?

V. Chohan LHC Project Workshop-Chamonix XIV, Jan Possible Concerns & Worries 3. Is the production reliable that our test programme remains stable –Will additional tests like “Diode test” at cold be introduced or means found otherwise (at warm) for production control? 4. Other (newer) demands on SM 18 operation –Dynamic effects at injection, sufficient time resolution for decay/snapback, degaussing cycles etc, all need new additional studies. Even if conducted on fewer magnets, they take long time and upset the normal tests rhythm because the magnet remains on the bench a long time at cold. (and keeps a higher priority). Will similar (newer) requests be made ?

V. Chohan LHC Project Workshop-Chamonix XIV, Jan Possible Concerns & Worries 5. Can others cope with faster throughput? –ICS Consortium Contract Labour Do they have adequate manpower to absorb the increased work load –Equipment Support The fact that we have “Generalized Equipment support as opposed to specialized support as found in 24 Hr. operation in CERN” causes delays in solving problems and hence reduces our ability to test magnets faster

V. Chohan LHC Project Workshop-Chamonix XIV, Jan Possible Concerns & Worries 6. ROCLA – ROCLA suffered from breakdowns in 2004, with dramatic effects; similar issues would jeopardise our desired test rates –Presently the ROCLA operation staff do not work 24 hrs, but with the projected magnets per month, it is imperative that a change in working hours will be required. Our experience with ICS says that these things do not happen overnight.

V. Chohan LHC Project Workshop-Chamonix XIV, Jan Conclusions 1.Different Projections with end-2006 goal in mind have been presented showing that testing of what we do know ( Dipoles & Arc-SSS) must go faster to permit more time for the unknown ( IR-SSS) 2.The IR SSS testing, particularly magnetic measurements will have to be based on sampled or Type testing and utilising all our known measurement systems and facilities both in SM18 and Block 4 on Prevessin site ( MAC Dec 04, Review Jan 05 ) 3.Despite many unknowns we believe that there is a reasonable chance of terminating the test programme in time by end 2006 OR early months of “Optimism is the faith that leads to achievement. Nothing can be done without hope and confidence“.....Helen Keller (American author and educator who was blind and deaf )

V. Chohan LHC Project Workshop-Chamonix XIV, Jan Thank You Thanks to the OP Team for providing the Input for this talk. Acknowledgements are also due to to all the past & present members of the SM18 Operation Team from DAE-India & AB Dept, CERN to bring the Tests Programme to the level where it is today, together with all the other Support Teams ( MTM- Equipment, Cryogenics, ICS, Power convertor)