Vacuum, Surfaces & Coatings Group Technology Department (some) Other non-solved NC across the LHC ring and potential impact on performances V. Baglin CERN TE-VSC, Geneva 2 LHC Performance Workshop, Chamonix,September 22-26, Systems at Cryogenic Temperature 2. Systems at Room Temperature 3. Conclusions

Vacuum, Surfaces & Coatings Group Technology Department 3 LHC Performance Workshop, Chamonix,September 22-26, Systems at Cryogenic Temperature

Vacuum, Surfaces & Coatings Group Technology Department A total of 3443 out of which 456 are consolidated i.e. 13 % ARCs All arc RF-ball test ok before cool down 2 PIMs found buckled after warm up: Arc 81: QQBI.14L1, V1 Arc 12: QBQI.33R1, V2 (already warmed up in 2009) Arc extremity QQBI.7R and QBQI.8L consolidated during LS1 PIMs repaired when magnets are consolidated Semi-SAM All checked ok by tomography except: D3-LU (QBUI.5L4) in LSS4L D2-Q4 (QBQM.4R2) in LSS2R 4 Plug-In Module NCs Impact on LS-TS & operation: Warmup above 120 K requires inspection Impact on LS2: none (if no modification of consolidation strategy) LHC Performance Workshop, Chamonix,September 22-26, 2014 QQBI.14L1.B2 Inner Triplets Checked ok by endoscopy QBQI.33R1 Deformed finger in QBUI.5L4 Deformed finger in QBQM.4R2 All data courtesy of C. Garion

Vacuum, Surfaces & Coatings Group Technology Department 5 IT aperture Endoscopy of all the triplets LHC Performance Workshop, Chamonix,September 22-26, 2014 Beam line Inspected (C. Garion) Ok in point 1,2 and 8 Point 5R: Protusion of small contact strip in Q1/Q2 interconection Already indentified in 2009 No evolution since then Decision to use as is (LBOC 17/9/2013) QQQI.2R5: contact strip protrusion Impact on operation and LS2: none

Vacuum, Surfaces & Coatings Group Technology Department 6 UFO: Beam line cleaning Following UFO storms observations in some areas: mainly S34 LHC Performance Workshop, Chamonix,September 22-26, 2014 Courtesy of T. Baer Beam line Inspected (C. Garion LMC 28/10/2013) S34 area: 25R3.B2, 19R3.B1,13R3.B1: Cell 13R3.B1 : local oxidation B2 line of cell 28R7, arc 78: few debris removed. B2 line of cell 16L3, arc 23: few scratches observed 1 fibre removed A20R3: Dirty BS 1 fibre removed Q19R3: contact strip protrusion repaired Only some MLI removed from S34 i.e. 99 for ~ 6 km of beam screen ! No systematic observation of debris where UFO are observed No clear correlation between UFOs and debris Impact on LS2: none

Vacuum, Surfaces & Coatings Group Technology Department The 7 major leaks (created during thermal transient) were repaired during LS1: S34: repair of line M, cold mass circuit, A27L4.M S45: repair with TE-CRG of QRL SubS B, line C QRL leaks due to multiply bellows failure 7 Leaks: Insulation Vacuum LHC Performance Workshop, Chamonix,September 22-26, 2014 Collateral damage during LS1 created leaks >10 -7 mbar.l/s (repaired) Insulation vacuum system in sectors cooled down: behaviour as expected so far ! Impact on LS-TS & operation: thermal transient (quench, warm up) increases the risk of major leak Impact on LS2: several leaks to repair (IT5L, DFBAK, A23R8.M …) Leaks level: Run 1 : leaks >10 -5 mbar.l/s After LS1: leaks mbar.l/s range, except six < mbar.l/s All data courtesy of P. Cruikshank, J. Perez Espinos

Vacuum, Surfaces & Coatings Group Technology Department 8 Beam Screens All beam screen heaters have been consolidated to allow heating at 200 W. Only the heater of Q20L2 is not operating => “non standard” solution will be use to warm up the beam screen if needed Upgrade of the beam screen valves in s34, some SAM and semi-SAM to reach same level of cooling capacity around the ring LHC Performance Workshop, Chamonix,September 22-26, 2014 K. Brodzinski, G. Ferlin, L. Tavian Impact on operation: Local cooling capacity of the beam screen is homogenized and upgraded to ~2 W/m for scrubbing Allows for a full usage of the cryoplants available capacity (estimated at ~1.6 W/m per aperture)

Vacuum, Surfaces & Coatings Group Technology Department 9 LHC Performance Workshop, Chamonix,September 22-26, Systems at Room Temperature

Vacuum, Surfaces & Coatings Group Technology Department 10 Collimator 5 th axis NC LHC Performance Workshop, Chamonix,September 22-26, 2014 TCTPs in IP1 and IP5 have their 5 th axis condemned Very tight area Integration of 5 th axis components is not possible Solution under study based on a longitudinal movement of TCTP Integration to be validated New interconnecting modules to be designed and procured ECR Courtesy of Y. Muttoni LSS5L LSS1L Impact on operation: cannot afford the risk to damage TCTPs Impact on YETS 2015: interventions in A4L1, A4R1, B4L5, B4R5 Impact on LS2: none

Vacuum, Surfaces & Coatings Group Technology Department 11 RF bridge NCs LHC Performance Workshop, Chamonix,September 22-26, NCs identified during Run1 Spread over 52 RT vacuum sector (LHC total is 185) All fixed during LS1: 29 RT vacuum sectors were opened for this purpose X-ray control of repaired VM are underway Courtesy of A. Piguiet Impact on LS1 & TS: continuation of X-ray campaign Impact on operation: none identified so far Impact on LS2 & LS3: development of new RF bridges for radioactive areas Deformed RF finger with spring out Courtesy of J. Perez Espino

Vacuum, Surfaces & Coatings Group Technology Department 12 MKBs NC LHC Performance Workshop, Chamonix,September 22-26, 2014 Known NC since LHC installation Huge outgassing rate (plastic !) Pumping system upgraded during LHC installation to faster pump down But 400 l/s ion pumps get destroy under large gas load LS1: new VPI 10/10 for MKB4R and 4/10 for MKB4L Run 2: Development of a new pumping scheme to be launched Impact on operation: potential ion pumps trips / destruction Impact of TS and EYETS : potential replacement of ion pumps Impact on LS2 : possible upgrade of the pumping scheme Courtesy of V. Senaj

Vacuum, Surfaces & Coatings Group Technology Department 13 Description of bake-ability NCs LHC Performance Workshop, Chamonix,September 22-26, 2014 Some components cannot be baked to nominal performances with nominal heating rates and nominal bake out system Usual origin is mechanical reason, sometime electrical reason May implies larger gas load May implies bake out longer time i.e. two weeks vs the one week base line May implies sensitivity to leak opening Impact on operation: increase of background to the experiments reduction of NEG coating life time Impact of TS and EYETS : longer intervention time increase risk of leak during the bake out Impact on LS2 : possible upgrade of specific equipments

Vacuum, Surfaces & Coatings Group Technology Department Impact on operation: none if no need to open the concerned vacuum sectors reduction of NEG coating life time Impact of TS and EYETS : very long intervention time with large risk of leak during the bake out Impact on LS2 : possible modification of the extremities or sectorisation 14 Bake-ability NCs: TCDQ LHC Performance Workshop, Chamonix,September 22-26, 2014 At surface, TCDQ are validated in an oven (with stops at 80 and 120 deg) Several leaks opened during LS1: systematically at the same place TCDQ are installed in a long vacuum sector 115 m Actual bakeout duration is 2 weeks (heating rate 13 deg/h and stops at 80 and 120 deg) Studies should be conducted during Run2 to understand the origin

Vacuum, Surfaces & Coatings Group Technology Department 15 Bake-ability NCs: BGIs LHC Performance Workshop, Chamonix,September 22-26, 2014 Impact on operation: increase of R2E levels reduction of NEG coating life time Impact of TS and EYETS : none Impact on LS2 : possible upgrade of this specific equipment At surface, several leaks opened during validation phase, systematically on the same feedtrough Given the approaching sector closure, it was decided to apply a reduced bakeout temperature : 140 deg at 10 deg/h Developments should be conducted during Run 2 to reach LHC nominal performances (250 deg and 50 deg/h)

Vacuum, Surfaces & Coatings Group Technology Department 16 Bake-ability NCs: BWS LHC Performance Workshop, Chamonix,September 22-26, 2014 During LS1, the construction of the BWS could not be delivered in time with the required robustness at the bellow’s weld Given the approaching sector closure, it was decided to apply a reduced bakeout temperature : 120 deg at 25 deg/h Developments should be conducted during Run2 to reach LHC nominal performances (250 deg and 50 deg/h if the motor is enough far away from the bellow) Impact on operation: increase of R2E levels reduction of NEG coating life time Impact of TS and EYETS : none Impact on LS2 : possible upgrade of this specific equipment

Vacuum, Surfaces & Coatings Group Technology Department 17 Bake ability NCs: Cristal collimation LHC Performance Workshop, Chamonix,September 22-26, 2014 Impact on operation: increase of R2E levels reduction of NEG coating life time Impact of TS and EYETS : working in a high radiation area Impact on LS2 : possible upgrade of this specific equipment See LMC 173 : 5/5/2014 – W. Scandale Located in LSS 7 beside collimators: ALARA issue Limited bakeout temperature : 110 deg at 10 deg/h due to the presence of piezzo electric material If the experiment is foreseen to stay in LHC, developments should be conducted during Run2 to reach LHC nominal performances (250 deg and 50 deg/h)

Vacuum, Surfaces & Coatings Group Technology Department 18 Virtual (internal) leak NC LHC Performance Workshop, Chamonix,September 22-26, 2014 ~ 1200 vacuum components were qualified at surface before tunnel installation Outgassing rate Cleanliness Leak detection Some equipment exhibit large virtual leaks: Traced by Ar BQSV.5R4.B1: mbar.l/s TCSP. 4L6.B2: mbar.l/s Impact on operation: possible saturation of NEG coating possible loss of conditioning in the nearby stand alone magnets Impact on LS2 : upgrade of the concerned equipment Courtesy of G. Cattenoz As a result of virtual leaks, the leak detection sensitivity limit in the concerned vacuum sector is altered Design : leak rate < mbar.l/s so the leak rate per component < mbar.l/s

Vacuum, Surfaces & Coatings Group Technology Department 19 Ferrites and potential heating NCs LHC Performance Workshop, Chamonix,September 22-26, 2014 Impact on operation: possible pressure rise Impact on LS2 : possible upgrade of equipments Ferrites inserted in devices (XRP, TCSP, TCTP, MKI, TDI …) can heat up during operation => increase outgassing rate TT2-111R, CMD5005 and CMD10 Treated at 400 ° C – 1000 ° C Courtesy of G. Cattenoz °C

Vacuum, Surfaces & Coatings Group Technology Department 20 TDI LHC Performance Workshop, Chamonix,September 22-26, 2014 TDI was sectorised during LS1 => allow exchange/reconditioning if needed Pumping system was upgraded with NEG cartridge However, TDI will still suffer from (see B. Salvant presentation) Resistive wall, ~ 400 W on jaws at injection and 60 W at flat top (jaw in parking position) Trapped modes Beam induced heating and outgassing Both TDI base pressure are back to nominal values Impact on operation: need beam conditioning, possible beam induced outgassing Impact of TS and EYETS : possible exchange of TDI Impact on LS2 : probable upgrade of the TDI system no beamwith beamno beamwith beamno beam TDI2L ~ TDI 8R ~

Vacuum, Surfaces & Coatings Group Technology Department 21 Damage and potential NCs LHC Performance Workshop, Chamonix,September 22-26, 2014 Impact on LS1 : repair =>longer activity time Impact on operation, TS and EYETS : none Impact on LS2 : continue to upgrade quality and reinforce QC teams During LS1, the vacuum system suffer from collateral damages, examples : Accidental venting : VMAAQ beside DFBX 5R: leak tight Damage on beam pipe Consolidated with reinforcement sleeve Courtesy of P. Cruikshank at 12:28: vacuum sector vented for unknown reason Uncontrolled pumping: Just before s78 cool down: a tractor snatch the pumping group and vented the sector : a port sealed with Al explodes due to pump down => 1.5 month cleaning

Vacuum, Surfaces & Coatings Group Technology Department 22 Summary During LHC installation and Run 1 several NC were identified Most of them were cured during the LS1, remains mainly: 5 th axis implementation in recombination area MKB large outgassing rate Potential issues with RF bridges are under control However the reinforced quality control during LS1 reveals new issues such as : compatibility of components with a bake-able system presence of virtual leaks Quality assurance and control remains and important part of the activity to guarantee the performances Several impact on operation, TS: warm-up, thermal transient, background, R2E, NEG ageing, intervention time, conditioning loss, pressure rise etc. Identification of specific consolidation for LS2 LHC Performance Workshop, Chamonix,September 22-26, 2014

Vacuum, Surfaces & Coatings Group Technology Department 23 LHC Performance Workshop, Chamonix,September 22-26, 2014 Acknowledgments Many thanks to P. Cruikshank, J. Perez Espino, C. Garion, G. Cattenoz, G. Bregliozzi, G. Ferlin, K. Brodzinsky and L. Tavian for their contributions to this presentation

Vacuum, Surfaces & Coatings Group Technology Department 24 LHC Performance Workshop, Chamonix,September 22-26, 2014 Thank you for your attention !

Vacuum, Surfaces & Coatings Group Technology Department C4L5 B2 B1 ColUMM Y. Muttoni EN- MEF-INT 5th Axis OK VAMWF ± 2mm VVGSM VMPNB ± 2mm VMHAA ± 2mm 5th Axis Ko 5th Axis Ko VAMTZ ±10mm VAMTS ± 10mm

Vacuum, Surfaces & Coatings Group Technology Department 27 LHC Performance Workshop, Chamonix,September 22-26, 2014 Cryosorption pumping Continuous turbo pumping Additional turbo pumping Cannot be pumped 10 -2, mbar.l/s Helium Leak rate (Cold, RT) 1 cryomagnet leak (S34) 1 QRL leak 17 cryomagnet leaks Triplet 5L DFBAK (DFBA CL flexibles in 2009) A8R6.M QRL ssH 7-8 Several others pre-LS1   Created in thermal transients 1 QRL leak (S45) A23R8.M 10 -4, mbar.l/s Triplet 5L DFBAK A23R8.M Run 1After LS1During LS1 5 QRL leaks (warm up) A23L5.M A7L8.M QRL ssB 2L 8 leaks (LS1 activities) 3 leaks (flexibles) 5 leaks (flexibles) 9 leaks (10 -7 mbar.l/s) Many others (range <10 -7 mbar.l/s) A23L5.M A7L8.M QRL ssB 2L 3 leaks (10 -7 mbar.l/s) Triplet 5R A27L8.M A19L5.M Range mbar.l/s Several others (range <10 -7 mbar.l/s)