SMACC Eighteenth report [20 min] 07/02/2014 Jean-Philippe Tock (TE-MSC) On behalf of the SMACC project

Activities since last LSC (24/01/2014) Arc splices installation By Activities By sectors SIT DFBA Dashboards Specials Quadrupole diodes Overheated splices Activities for the next 2 weeks Conclusions

SMACC Main activities for the last 2 weeks Sector 56 : Final leak test and surface work on DFBAK SHM Investigation on dipole diodes Sector 67 : Pressure test successfull Purge, ElQA, Flushing (CRG/MPE): Not formally SMACC project Sector 78 (Not priority) Work on NC Work on DFBAO at the surface Sector 81 (Priority) Complete the M leak tests of non problematic Ics Progress on IC closure Sector 12 Progress on M lines rewelding Start M leak test Sector 23 Progress on the installation of electrical insulation Work on overheated splices Complete preparation for Q diodes consolidation Sector 34 Complete splices unsoldering Installation of shunts Sector 45 Start desoldering and resoldering of splices All is reclosed but the IC with DFBAK, DFBA SHM back in place Insulation vacuum leak tested on >90% of S56 Diodes exchanged, to be reclosed From last LSC (24.01.2014)    ElQA before flushing on-going… So far so good > 98% M lines leak tested, > 95% reclosed, Ins vac test started   SHM disconnected and at the surface  > 90% M lines are leak tested  > Half reclosed > 75% welded  QDiodes consolidation restarted  > 30% leak tested  >90 % done  On-going, see later  Stopped (See S12)  Completed  On-going, ≈ 90% done  On-going, First shunts are installed

SEQUENCE AND STATUS Completed Completed Completed Completed Cancelled Install DN200 Completed 100 % Completed Completed Completed OK to open Open ICs Open M sleeves 8 sectors 8 sectors 8 sectors Undo / Redo splices ElQC (new splices) Cancelled ≈ 7 sectors ElQC (old splices) Machine Cu ElQC after Cu mach. ≈ 7.5 sectors > 7 sectors ≈ 7 sectors Consolidate Q diodes Restarted, see later ≈ 4.9 sectors Install shunts ElQC after shunt Insulate splices Weld M Leak test M Close IC Final LT > 6.8 sectors > 6.5 sectors ≈ 6 sectors > 4.7 sectors > 4.2 sectors ≈ 3.5 sectors ≈ 2 sectors

Operator responsible : JM Hubert Last M line opening (S45) 6th of February 2014 Operator responsible : JM Hubert Pictures by M Struik

SMACC Progress report by activity Desoldering / Resoldering: Completed in about 7 sectors equivalent 78 78 Still OK Desoldering is completed in S34 About one week margin built wrt to Cu machining Desoldering should be completed by end of February Courtesy H Prin

SMACC Progress report by activity Shunts are installed in ≈ 6.8 sectors-eq (ICs ≈ 85%) Almost completed in 23 2 weeks ahead of schedule Mind the last X% effect Starts to saturate 9 Ics remains in the 6 first sectors Starts in 45, not really good news Shunt weekly installation rate (4 weeks sliding average) *Estimate for W6

SMACC Progress report by activity Insulation box: Installed in almost 6 sectors equivalent 92 (4 weeks sliding average) *Estimate for W6 Baseline recovered Only 24 ICs left in 6 first sectors (<2 %) Buffer of >3 weeks wrt welding Courtesy H Prin / G Maury

SMACC Progress report by activity M Welding : Almost 1000 ICs welded, > 4.7 sec-eq: Routinely 12 ICs/day Work concentrated in 1 sector Leaks investigations (See next slide) As presented LSC 4.10.2013 18 weeks @ 51 17 ICS behind forecast (Eq to < 2 days ; Recovered in <2 weeks) 11 weeks @ 34

SMACC Progress report by activity M Welding : Investigation on leaks: 4 leaks found Dec-13 (2 in S78 / 2 in S81) Investigations are completed Repair procedure to be applied in 78 defined, requires flange replacement (Cut of SC splices) Leaks localised after heat treatment of 950 °C / 2 hours QQBI.25R8 M1L Leak rate 2.7 10-7 mbar.l/s Position 6H opposite to the weld seam in the base material of the flange. Magnet HCLQOAO001-CR000095 Findings: Numerous sulphides No imperfection on the weld Macro-inclusion at leak location AISI 304 grade type with high S content (possible free machining grade) QBBI.A27R8 M1R Leak rate 5.8 10 -8 mbar.l/s Position 3H opposite to the weld seam in the base material of the flange. Magnet HCLBALA000-IN001059 Findings: No imperfection on the weld Macro-inclusion at leak location Chemical composition analysis: on-going Flange base material: Numerous sulphides Risk of other cases like this Inventory of cold masses produced in the same time period No systematic replacement Procedure to apply in similar cases is defined Immediately apply it in case of such leaks are identified Courtesy S Atieh / A Gerardin (EN-MME)

SMACC Progress report by activity M sleeves leak testing : (889 ICs) are leak tested (> 4 sec-eq) Following the M lines rewelding About 1 month behind schedule Under recovery as for the M welding Courtesy P Cruikshank / L Mourier

SMACC Progress report by activity Reclosure of interconnections : ≈ 3.5 sec equivalent are reclosed Work in 2 sectors, mainly 81 On the baseline OK with the modification of the thermal shields, just in time

SMACC Progress report by activity Final leak test: Almost 2 sec equivalent completely validated 3 weeks to have results after repumping S56: only DFBAK subsector remains S67: fully validated S78: 1 subsector validated, 11 under test (out of 14) S81: 3 subsectors under test About 4 weeks behind schedule

SMACC Progress report by activity Final leak test: Leak discovered on DN200 Two leaks discovered on first subsector in 78 Repair procedure for the weld is likely OK First time we see a leak in the material of the DN200 flanges Repair procedure to be defined

W6 : He spill test during the nights (Access restrictions) SMACC Sector 67 ElQA is on-going To come: Flushing ElQA Campaign to fix NCs (leaks, thermometer, possible short circuits in diodes, ?) beginning of March 14 SMACC Sector 45 W6 : He spill test during the nights (Access restrictions) First shunts installed W7 : Reopening of the ICs that were temporarily reclosed

SMACC Progress report by sector Main activities are : Leak test of M lines Reclosure of IC Rate is OK with baseline forecast provided that almost continuous work Main activities are : The welding of M lines Leak test of M lines

SMACC Progress report by sector Main activities are : Installation of electrical insulation > 90% completed Work on overheated splices (More info in next slides) Consolidation of Q diodes Main activities are : Splices redoing (Almost completed) Cu machining Shunt installation Preparation of insulation

SMACC Dashboards Opening is completed Shunting is ahead of schedule but will slow down (Difficult cases ahead) The installation of insulation boxes has recovered the baseline Welding and M leak test rates are more than required to recover baseline schedule Reclosure: On baseline, nominal rate achieved Insulation vacuum leak test : To follow-up, one sector equivalent under test

 Completed New New New New  Completed

SMACC Progress report SIT Team members are partially reinforcing the train and the DFBA activities Activities linked to NC and overheated splices Intervention on triplet braids has started on the two triplets at P2 Courtesy N Bourcey, S Le Naour

SMACC Progress report SIT : Interventions on triplets braid Q1R1/Q1L5: Install braids (2009) Q1L1/Q1R5: Remove braids (LS1) Q1L2/Q1L8: Remove braids (On-going at L2) Q1R2/Q1R8: Install braids (On-going at R2) D1L2/D1L8: Remove braids on DFBX side D1R2/D1R8: Remove braids on arc side Consolidation of triplet braids On-going at P2 (Supervised area) Rehearsal for the procedures according the ALARA principle Courtesy N Bourcey, S Le Naour

SMACC DFBA 94 / 135 splices consolidated (70%) work completed on 4 DFBAs. 129 /135 splices accessible (96%) Just in time for the splicing team Courtesy A Perin

SMACC DFBA Repair of short on pigtail #6 @ DFBAO Common effort of TE-MSC, TE-MPE, EN-MME, TE-CRG Location of insulation problem (TE-MSC) Pigtail after removing iinsulation(TE-MSC) Pigtail being repaired (TE-MSC) Repaired insulation High voltage tests (TE-MPE) Courtesy A Perin, R Principe

SMACC DFBA Specific support at DFBAL2: NC 1329774 Common effort of TE-MSC (CMI and LMF), TE-CRG Splices were unsoldered to avoid stressing them Badly positioned spider Badly positioned spider removed New support in position Courtesy A Perin, A Vande Craen

SMACC Dashboards Decreasing delay  Delay stable Arc splices: Baseline: 69.3 % (67.8 %) Completed: 64.9 % (63.9 %) Delay 22 (24) days Baseline: 70.6 % (66.5 %) Completed: 70.1 % (64.4 %) Delay 2 (7) days Decreasing delay  Delay stable Arc splices: Rates are stable All activities are still on-going Trend should remain in the next 1-2 months Main delay is in S12 DFBA: Ahead of the new baseline

SMACC Dashboards Progress: Baseline: 71.8% (67.8 %) Completed: 68.0% (63.7 %) Delay 13 (15) days Dercreasing ; Δbaseline <≈ Δcompleted

SMACC Quadrupole diodes (1/2) Quadrupole diodes : Reminder of the consolidation Courtesy L Grand-Clement, R Moron –Ballester, F Savary

SMACC Quadrupole diodes (2/2) Quadrupole diodes : Production Restarted thanks to a partially conform delivery of supplier 1 ! Sector 12 is completed but one NC case Sector 23 is restarted, components OK up to mid of 23 With delivery of supplier 3 expected in the coming days, OK up to 85% of S23 Impact on welding is minimum, no impact on other activities so far Could have large impact on VSC and CRG Plates manufacturing launched with a 4th supplier via main workshop (Thanks to EN-MME) with material that was available at MSC Several cases of un~ or badly coated BB in S23 to be analysed by diodes WG Report by F Savary in a next LSC Planning : ? Assuming that all pieces are conforming Assuming that all suppliers respect the schedules ….. We are OK for > 2 weeks so update at next LSC Courtesy L Grand-Clement, R Moron –Ballester, F Savary

SMACC Overheated splices (1/6) TE-TM on 04.02.2014 Magnetisation measurements of 5 mm-long strand samples extracted from LHC busbar cables can provide a quantitative assessment of cable damage caused by overheating in a minimal invasive way [Journal of Physics: Conference Series 234 (2010) 022031]. Variation of the Nb-Ti/Cu strand magnetization (ΔM) at 4.2 K in magnetic field up to 6 T after different HT’s (a) and relative flux pinning reduction vs. annealing temperature at different magnetic field (b). Strongly overheated and brittle busbar cable found in the LHC in 2009 [Non-conformity report EDMS No. 992513]. Courtesy C Scheuerlein, F Savary

SMACC Overheated splices (2/6) TE-TM on 04.02.2014 Strongly overheated splices can be detected by visual control of the busbar insulation. Degradation of max 50% at 0.7T Extraction of 5 mm-long strand samples for magnetisation measurements Busbar adjacent to splice QBBI.A21L6-M2-Int (NCR EDMS No. 1290623). The insulation has been degraded by excessive heating. Courtesy C Scheuerlein, F Savary

SMACC Overheated splices (3/6) TE-TM on 04.02.2014 LS1 – Overheated Splices Repair procedure N. Dalexandro, E. Grospelier, H. Prin, R. Principe, F. Savary, P. Voisin Courtesy C Scheuerlein, F Savary

SMACC Overheated splices (4/6) Surgeons @ work TE-TM on 04.02.2014 LS1 – Overheated Splices Repair procedure N. Dalexandro, E. Grospelier, H. Prin, R. Principe, F. Savary, P. Voisin Courtesy C Scheuerlein, F Savary

SMACC Overheated splices (5/6) TE-TM on 04.02.2014 7.5 sectors are inspected so far Electrical risk is limited (large margin on the Jc) Mechanical risk has not to be underestimated Procedure developped, avoiding to replace magnets, able to produce very high quality splice with some associated risk (Only expert technicians) Capacity of 2-3 splices per month Consider only splices that have not to be opened for another reason (R_8, geometry, R@cold) 24 splices concerned (< 1/400), could be 26 6 have already been repaired (6th this week) Courtesy C Scheuerlein, F Savary

SMACC Overheated splices (6/6) TE-TM on 04.02.2014 Category # Splices repaired with new cables 6 Splices needing to be repaired with new cables 5 Overheated splices, pending decision 7 Slightly overheated splices, redone standardly 3 Splices not yet opened, could be consolidated as is Strategy defined at TETM Margin is high on Jc Consolidate not yet opened splices “as is” (without opening) Resolder slightly overheated splices in a standard way if solderability ensured Based on this, identify other opened splices that could be repaired standardly Complete inspection Train new technicians for the less critical operations (Small effect on productivity) Review the situation in the coming weeks Courtesy C Scheuerlein, F Savary

Very slightly more than nominal rate achieved these last 19 weeks ! SMACC Summary on progress Main 13 kA Splices:  Delay reduces  Availability of components for QDiodes consolidation  Overheated splices repair can become critical Special Interventions:  Delay stable, start last planned interventions (triplets) DFBA:  Activities have started on all standard DFBAs  DFBAK is back in the tunnel  Back in the shadow of arc splices (except 56-78) SMACC:  About 2 weeks of delay Delays are sligthly reducing Very slightly more than nominal rate achieved these last 19 weeks !

SMACC Main activities for the next 2 weeks Sector 56 : Final leak test and start reconnection of DFBAK Sector 67 : Pressure test successfull Complete ElQA, Flushing (CRG/MPE): Not formally SMACC project Sector 78 (Not priority) Work on NC Work on DFBAO at the surface Sector 81 (Priority) Complete the M leak tests of non problematic Ics Progress on IC closure Sector 12 Compete M lines rewelding Continue M leak test Sector 23 Progress on the installation of electrical insulation Work on overheated splices Continue Q diodes consolidation (as long as components allows) Sector 34 Complete splices unsoldering Installation of shunts Sector 45 Continue desoldering and resoldering of splices

Conclusions Delays are reducing Mind the last X % (S78 is at 93%) effect… DFBA consolidation is progressing very well  Issues: Overheated splices Other diodes issues (Diodes WG-MPE/MSC) Components for consolidation of quadrupole diodes (More news in 2 weeks) Repair of NCs in parallel with production work (March in 67)

Operator responsible : JM Hubert Last M line opening (S45) 6th of February 2014 Operator responsible : JM Hubert Pictures by M Struik