1 st HiLumi LHC/LARP Collaboration Meeting 18 November 2011

1. Cold Powering and Superconducting Links A. Ballarino, CERN 1stHiLumi LHC/LARP Collaboration Meeting 18 November 2011

2. Outline • Cold Powering of LHC low- triplets • Remote powering via superconducting links • Development at CERN of HTS superconducting lines • WP6 of the Hi-Lumi Collaborative Project • Conclusions A. Ballarino, 18 Nov. 2011

3. Hi-Lumi upgrade: Reduce * by stronger and larger aperture quadrupole magnets located near the collision points (low- triplet quadrupoles). Increase of Bp that can be transformed in higher quadrupole gradient or/and larger bore diameter Nb3Sn Iop = 15 200 A Bp = 11.9 T Gradient = 171 T/m Cold powering system: Provide an “efficient” electrical transfer from the power converters, at room temperature, to magnets. It’s a cryogenic and electrical system that incorporates superconducting components A. Ballarino, 18 Nov. 2011

4. A. Ballarino, 18 Nov. 2011

5. A. Ballarino, 18 Nov. 2011

6. SCHEMATIC LAYOUT OF THE low- TRIPLET Distances in m MQXA A. Ballarino, 18 Nov. 2011

7. Layout at Point 1 DFBL 3.6 m Q3,Q2,Q1 Q11, Q10…Q7 DFBA Q6 Q5 Q4,D2 D1 DFBX TAS TAN IP 8 IP1 4.5 K 4.5 K 1.9 K 3 m 12 m RR 13 UJ 13 A. Ballarino, 18 Nov. 2011

8. POWERING CONFIGURATION OF THE TODAY LHC INNER TRIPLETS • Nestedcircuits • One trim power converter on Q1 DFBXA and DFBXB at P1 DFBXE and DFBXF at P5 Itot 40 kA F. Bordy et al. D1 at P1 and P5: resistive magnet Q1, Q2 and Q3: four leads, each rated at 7500 A DC Corrector magnets: quadrupole, sextupoleoctupole (120 A/600 A) A. Ballarino, 18 Nov. 2011

9. POWERING CONFIGURATION OF THE HIGH LUMINOSITY –NEW- INNER TRIPLETS • Individual powering of each circuit ? • Nested powering, e.g. one main power converter plus current trimming on each magnet ? • Split powering, e.g. Q1 in series with Q2a and Q3 in series with Q2b ? • Need for energy extraction via warm resistors of each individual magnet, i.e. need for • safety leads and additional superconducting cables in the cold bus ? • Time constant of the circuits and amount of stabilizer in the cables ? D1 at P1 and P5: resistive magnet Q1, Q2 and Q3: four leads, each rated at 7500 A Corrector magnets: 120 A (dipole) and 600 A (sextupole) resistive magnet  superconducting magnet, I 10 kA four leads, each rated at 7500 A  eight to four leads, each rated up to 15 kA Itot 40 kA  40 kA  > 100 kA A. Ballarino, 18 Nov. 2011

10. Layout at Point 1 DFBL 3.6 m Q3,Q2,Q1 Q11, Q10…Q7 DFBA Q6 Q5 Q4,D2 D1 DFBX TAS TAN I I IP 8 IP1 4.5 K 4.5 K 1.9 K 3 m 12 m RR 13 UJ 13 A. Ballarino, 18 Nov. 2011

11. Room temperature Cryogenic environment (4.5 K LHe in the DFBs) Cold powering system: 1) Current leads in a distribution cryostat (near the power converters); 2) Vertical electrical transfer (link); 3)Horizontal electrical transfer (link); 4) Cryogenic fluid supply and control; 5) Interconnection to the magnets bus system; 6) Protection of link and current leads. Tunnel

12. PM 54 DFBXE (RZ54) DFBXF (UJ56) PM 15 DFBXA (UJ13) DFBXB (UJ16) A. Ballarino, 18 Nov. 2011

13. 2100 kA A. Ballarino, 18 Nov. 2011

14. Point 5 Y. Muttoni J.P. Corso

15. A. Ballarino, 18 Nov. 2011

16. Powering via Superconducting Links • Free space in the beam areas; • Safer long-term operation of powering equipment located in radiation-free environment; • Safer and easier access of personnel to power converters, leads and control equipment; • Reduced time of interventions (maintenance, repair, diagnostic and routine tests) → • Gain in machine availability A. Ballarino, 18 Nov. 2011

17. Conductors in Superconducting Links MgB2 MgB2 Tape : 3.640.65 mm2 MgB2 : 12 % Cu : 15 % YBCO YBCO Tape : 4 0.1 mm2 YBCO: 1-3 m Cu : 220 m Bi-2223 Bi-2223 Tape : 4.5 0.4 mm2 BSCCO: 23 % Cu : 250 m A. Ballarino, 18 Nov. 2011

18. Conductors in Superconducting Links YBCO MgB2 Ic(77 K, self field)  100 A A. Ballarino, 18 Nov. 2011

19. Minimum quench energy of superconductors MgB2 cable 6 kA at 20 K (> 12 kA at 4.5 K) Nb-Ti cables used in LHC 6 kA at 6 K Nb-Ti, Top = 5 K Tc= 6 K → MQE = 2.63 mJ/cm3 Tc = 7 K → MQE = 5.26 mJ/cm3 Tc = critical temperature Top = operating temperature MQE= Minimum Quench Energy 6 mm A. Ballarino, 18 Nov. 2011

20. Cryogenics for Cold Powering System 20 K-50 K Tunnel A. Ballarino, 18 Nov. 2011

21. Where else in the LHC ? P5 P5 P7 P1 P7 Underground Installation A. Ballarino, 18 Nov. 2011

22. Current Leads and Power Converters ~ 250 m ~ 250 m Two links each about 500 m long 48 cables rated at 600 A per link Option also for P3 A. Ballarino, 18 Nov. 2011

23. S.Weisz, J. Osborne A. Ballarino, 18 Nov. 2011

24. What do we have today ?

25. CERN Prototype Link 25 × 2 × 600 A (2 × 15 kA) @ 35 K MgB2 @ 65 K (YBCO and Bi-2223) Link for Point 7 • 2 kg/m • 200 mHTS/mcable  = 40 A. Ballarino, 18 Nov. 2011

26. Test of 600 A HTS Cables MgB2 YBCO Bi-2223 MgB2 YBCO Bi-2223 600 A Measurements @ Southampton University (gas cooling) and CERN (liquid helium and liquid nitrogen). Length of HTS cables  2 m Proceedings of EUCAS 2011 A. Ballarino, 18 Nov. 2011

27. Test of CERN 600 A HTS Cables (CERN measurements) MgB2 (SOTON measurements) YBCO Bi-2223 600 A Top 15 K 55 K Proceedings of EUCAS 2011 A. Ballarino, 18 Nov. 2011

28. Cryostat for Link (20 m length) in SM-18 R=1.5 m A. Ballarino, 18 Nov. 2011

29. Cryostat for Link (20 m length) in SM-18 Semi-flexible line in SM-18 test station A. Ballarino, 18 Nov. 2011

30. High-current cable configurations MgB2 round wire 3 × 6 kA • 27 cables 6000 A • 48 cables 600 A • Itot = 190 kA @ 20 K (2 × 95 kA) • 5 kV  = 15.5  = 75 • 10 kg/m • 900 mHTS/mcable YBCO tape 24 × 6000 A 42 × 600 A Itot = 169 kA & 20 K ( 2 × 84.5 kA)  5 kV  =70 A. Ballarino, Proceedings of ASC 2010 A. Ballarino, 18 Nov. 2011

31. High-current cable configurations MgB2 round wire 7 × 14 kA, 7 × 3 kA and 8 × 0.6 kA cables – Itot120 kA @ 30 K Φ = 62 mm Development of round wire at Columbus Superconductors A. Ballarino, 18 Nov. 2011

32. CHALLENGES • Significant/unprecedented high-current long HTS cables (up to 15 kA) • Complex multi-cable assembly • Significant/unprecedented vertical transfer ( 100 m) • Need for reinforcement of cables (10 kg/m  1000 kg) • Need for appropriate compensation of thermal contraction in the straight • vertical part • Complex system to be integrated in the LHC machine A. Ballarino, 18 Nov. 2011

33. Work Package 6 WP 6, CERN A. Ballarino A. Ballarino F. Broggi (CERN,INFN) Task 1 Coordination Task 2 Cryogenics U. Wagner (CERN) Task 3 Electr. Transf. Cryostat Y. Yang (Univ.South.) Accelerator Physics and Performance Task 4 Energy Dep. Material F. Broggi (INFN) Fluka team Collimators Magnet Design Crab cavities

34. OVERVIEW OF GLOBAL ACTIVITY Hi-Lumi FP7 WP6 CERN activity CERN activity Design study Design study Integration Task 1 Coordination CERN/INFN • Prototypes construction • Cryostat • - Prototypes test • - System design • - Series specification • - Series construction • - Integration • - Operation Civil engineering Interfaces (mech, vacuum, electr) Task 2 Cryogenics CERN Vacuum Task 3 Electr. Transf. Cryostat Univ. South SC cables/SC link Cryostat of SC link Task 4 Energy Dep. Material INFN Current leads Protection Fluka team

35. Timeline HTS Links in LHC P1, P5,P7 HTS Links in LHC Hi-Lumi P1 and P5 Test of horizontal links Test of vertical links 2012 2014 2018 2020 Civil Engineering Superconductor System production 2012-2013 2018-2019 2020-2021 L. Rossi, Hi-Lumi LHC Design study A. Ballarino, 18 Nov. 2011

36. Integration of CERN HTS Prototype Link (5 m) in cryostat @ SOTON Successful test of 5 m long CERN prototype link (50 cables rated @ 600 A) He gas @ 30 K A. Ballarino, 18 Nov. 2011

37. Thanks for your attention A. Ballarino, 18 Nov. 2011