1. Triplet status and plans P. Ferracin, G. Ambrosio, M. Anerella, A. Ballarino, B. Bordini, F. Borgnolutti, R. Bossert, D. Cheng, D.R. Dietderich, B. Favrat, H. Felice, A. Ghosh A. Godeke, S. Izquierdo Bermudez, G. Manfreda, V. Marinozzi, M. Marchevsky, M. Juchno, S. Krave, J. C. Perez, H. Prin, L. Oberli, G. Sabbi, T. Sahner, J. Schmalzle, T. Salmi, M. Sorbi, E. Todesco, and M. Yu 3 rd Joint HiLumi LHC-LARP Annual Meeting Daresbury Laboratory, UK 11-15 November, 2013

2. Introduction MQXF overview 14/11/2013 Paolo Ferracin and Giorgio Ambrosio2 Target: 140 T/m in 150 mm coil aperture To be installed in 2022 (LS3) Q1/Q3 (by US LARP collaboration) – 2 magnets with 4.0 m of magnetic length within 1 cold mass Q2 (by CERN) – 1 magnet of 6.8 m within 1 cold mass, including MCBX (1.2 m) Baseline: different lengths, same design – Identical short model magnets SQXF Outline – Status of R&D and challenges: Conductor, cable, insulation Coil-structure design, integration Quench protection Planning by E. Todesco

3. LHC low-  quadrupole overview Present Nb-Ti low-  quadrupole – Nominal luminosity L 0 = 10 34 cm −2 s −1 – Integrated luminosity ∼ 300–500 fb −1 by 2021 2004, start of LARP Nb 3 Sn program – Same gradient in larger aperture for ultimate luminosity (2-3  L 0 ) 2008, two-phase upgrade – Phase-I, NbTi for ultimate – Phase-II, Nb 3 Sn for higher L 2012, large aperture Nb 3 Sn design – Increase the peak luminosity by a factor of 5 and reach 3000 fb −1 of integrated luminosity 14/11/2013 Paolo Ferracin and Giorgio Ambrosio3

4. Strand parameters Parameters used for magnet design 0.85 mm strand OST RRP (169 stack) Both 132/169 and 144/169 under consideration Bruker PIT (192) Cu/Sc: 1.2  0.1  55% Cu I strand = 361 A (15 T, 4.2 K) J sc = 1400 A/mm 2 I strand = 632 A (12 T, 4.2 K) J sc = 2450 A/mm 2 Common document with functional specifications under preparation Conductor/cable internal review held in Oct. 2013 14/11/2013 Paolo Ferracin and Giorgio Ambrosio4 PIT strand RRP strand

5. Cable parameters 40-strand cable Bare width x thickness: 18.150 x 1.525 mm SS core 12.7 mm wide and 25 μm thick Assumed growth during HT :4.5% (thickness), 2% (width) 14/11/2013 Paolo Ferracin and Giorgio Ambrosio5 PIT cable RRP cable Several samples prepared and tested Further optimization (within existing QXF cable envelope) to – Improve mechanical stability – Minimize cabling degradation

6. Cable insulation AGY S2-glass fibers 66 tex with 933 silane sizing 32 (CGP for CERN) or 48 (NEW for LARP) bobbins Variables: # of yarn per coil and of picks/inch Target: 150 μm per side Achieved by both companies 14/11/2013 Paolo Ferracin and Giorgio Ambrosio6

7. Coil 2D/3D magnetic design (By F. Borgnolutti, S. Izquierdo Bermudez, P. Hagen, G. Sabbi, X. Wang) 4-blocks, 2-layer with same angle 50 turns (22+28): max. G and distributed  Harmonics below 1 units at R ref =50 mm 6 blocks in the ends – b 6 < 1.1 unit; b 10 < 0.2 unit 1% peak field margin in the end Possibility of correcting low-order un-allowed harmonics with magnetic shimming 14/11/2013 Paolo Ferracin and Giorgio Ambrosio7

8. End spacers design (By D. Cheng, S. Izquierdo Bermudez, M. Yu) Two sets of plastic rapid prototype end spacers designed and fabricated Winding trials carried out both at CERN and by LARP External review of spacer design in 10/13 2 additional sets planned in Nov. 2013 Fabrication of metal end-spacers for first coil early 2014 14/11/2013 Paolo Ferracin and Giorgio Ambrosio8

9. Short coil practice winding and curing (By D. Cheng, S. Izquierdo Bermudez, M. Yu) 14/11/2013 Paolo Ferracin and Giorgio Ambrosio9 First short coils with Cu cable with plastic parts wound and cured (inner and outer layers)

10. Magnet parameters 632 A (12 T, 4.2 K) 361 A (15 T, 4.2 K) Self field corr. (ITER barrel) 0.429 T/kA 5% cabling degradation Godeke’s parameterization Operational conditions: 140 T/m I op : 17.5 kA B peak_op : 12.1 T 82% of I ss at 1.9 K G ss : 168 T/m I ss : 21.2 kA B peak_ss : 14.5 T Stored energy: 1.3 MJ/m Inductance: 8.2 mH/m 14/11/2013 Paolo Ferracin and Giorgio Ambrosio10

11. QXF magnet design 14/11/2013 Paolo Ferracin and Giorgio Ambrosio11 Target: 140 T/m in 150 mm coil aperture OD: 630 m SS shell, 8 mm for LHe containment Al shell, 29 mm thick Iron yoke – Cooling holes – Slots of assembly/alignment Master plates – 58 mm wide bladder Iron pad Aluminum bolted collars – Coil alignment with G10 pole key Ti alloy poles

12. LHC low-  quadrupole support structures Cold mass OD from 490/420 in MQXA-B to 630 mm in MQXF – More than double the aperture – ~4 times the e.m. forces in straight section – ~6 times the e.m. forces in the ends 14/11/2013 Paolo Ferracin and Giorgio Ambrosio12 MQXBMQXAMQXF In scale

13. Mechanical analysis (by M. Juchno) 14/11/2013 Paolo Ferracin and Giorgio Ambrosio13

14. Mechanical analysis (by M. Juchno) Peak coil stress: -160/-175 MPa with full pre-load (~90% of I ss ) Critical components during optimization – Shell stress after cool-down – Iron parts during assembly (  eqv ~200 MPa) – Iron parts after cool-down (  1 ~200 MPa) 14/11/2013 Paolo Ferracin and Giorgio Ambrosio14 Inner layer

15. QXF integration: Lhe containment (M. Anerella, B. Favrat, H. Felice, M. Juchno, J.C. Perez, H. Prin, T. Sahner) 14/11/2013 Paolo Ferracin and Giorgio Ambrosio15 Segmented aluminium shell for pre-load Separated SS shell for Lhe containment: 2 options – Inertia tube – Welded half shells Backing strip and tack welding block

16. Quench protection (G. Manfreda, V. Marinozzi, M. Marchevsky, T. Salmi, M. Sorbi, E. Todesco) Trace Heating stations in outer layer only with 50 μm polyimide ins. Heater delay of about 17 ms Before, 10 ms of validation and, after, 20 ms of outer-to-inner delay From simulations, hot spot T of 350 K (34 MIITS) Working group to define mitigation strategies Modelling of material properties (bronze) and quench-back + dI/dt effects Redundancy and CLIQ system Inner layer quench heater (50% open for cooling) 14/11/2013 Paolo Ferracin and Giorgio Ambrosio16 R dump = 46 mΩ V max = 800 V V max = 400 V

17. Planning (Work in progress) 14/11/2013 Paolo Ferracin and Giorgio Ambrosio17 CERN and LARP SQXF CERN and LARP Long prototypes CERN Series production LARP Series production

18. Planning 13/11/2013 G. Ambrosio and P. Ferracin18 Short model program: 5 CERN-LARP models, 2014-2016 – First magnet test in 05/2015 Long model program: 2 (CERN) + 3 (LARP) models, 2015-2017 – First magnet test in 08/2016 (LARP) Series production: 2017-2021 – 45 (CERN) + 90 (LARP in 2 production line) coil – 10 (CERN) + 10 (LARP in 2 production line) cold masses – Goal: cold-masses with cryostats ready for in installation by end of 2021

19. Conclusions MQXF: fully integrated CERN - LARP program – Same magnet design, different lengths Conductor and cable – Baseline strand, cable and ins. parameters defined (fine tuning in progress) – Cable fabrication for first set of short coils starts by the end 2013 / early 2014 Coil – Cross-section and end design defined – End spacer optimization in progress, first short coils fabricated Structure – Baseline design completed (2 identical 1.5 m long structures to be procured) – Aluminium shells procured and detailing design of components in progress Quench protection – Still challenging: calculated hot spot T ~350 K Several mitigation option under investigation SQXF – Coil fabrication starts in early next year. First test in 2015. 14/11/2013 Paolo Ferracin and Giorgio Ambrosio19

20. Appendix 14/11/2013 Paolo Ferracin and Giorgio Ambrosio20

21. Introduction IR layout (by E. Todesco) IR in the present LHC IR in the HiLumi LHC 14/11/2013 Paolo Ferracin21

22. Support structure From HQ to QXF Same structure concept with additional accelerator features – Pre-load capabilities of HQ design qualified and successfully tested – Larger pole key for cooling holes, cooling channels, alignment – assembly - handling slots, LHe vessel 14/11/2013 Paolo Ferracin and Giorgio Ambrosio22 HQ QXF

23. Coil 2D magnetic design (By F. Borgnolutti) Two-layer – four-block design Analytical model with sector coil (radial blocks) – 6 angles to optimize for field quality – 300 cross-sections identified Criteria for the selection – Maximize gradient and # of turns (protection) – Distribute e.m. forces in 2 layers and minimize stress Result: 22+28 = 50 turns – Close to maximum gradient and distributed stress All harmonics below 1 units at R ref = 50 mm 9% reduction of TF for saturation 14/11/2013 Paolo Ferracin and Giorgio Ambrosio23

24. LHC low-  quadrupole support structures 14/11/2013 Paolo Ferracin and Giorgio Ambrosio24 MQXB OD: 416 mm Aperture: 70 mm Coil width: 31 mm Coil OD: 132 mm Structure width: 142 mm F x_quad : 0.8 MN/m F z : 218 kN MQXA OD: 490 mm Aperture: 70 mm Coil width: 44 mm Coil OD: 158 mm Structure width: 166 mm F x_quad : 1.2 MN/m F z : 338 kN MQXF OD: 630 mm Aperture: 150 mm Coil width: 36 mm Coil OD: 222 mm Structure width: 204 mm F x_quad : 2.8 MN/m F z :1300 kN