Cold Powering and Superconducting Links A Ballarino CERN
Cold Powering and Superconducting Links A. Ballarino, CERN 1 st Hi-Lumi WP 6 kick-off meeting 17 November 2011
Hi-Lumi Collaborative Project FP 7 -Infrastructures Twenty participants Proposal submitted in 2011 WP 6 Cold Powering and Superconducting Links for LHC High Luminosity Upgrade WP 6 Participants: CERN, INFN, University of Southampton A. Ballarino, 17 Nov. 2011
Work Package 6 WP 6 Task 1 Coordination Collimators Crab cavities Task 2 Cryogenics Task 3 Electr. Transf. Cryostat Task 4 Energy Dep. Material Magnet Design Accelerator Physics and Performance Fluka team
Goal of 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 Nb 3 Sn option Iop = 15 200 A Bp = 11. 9 T Gradient = 171 T/m A. Ballarino, 17 Nov. 2011
A. Ballarino, 17 Nov. 2011
SCHEMATIC LAYOUT OF THE low- TRIPLET Distances in m MQXA A. Ballarino, 17 Nov. 2011
Layout at Point 1 3. 6 m DFBL 4. 5 K Q 11, Q 10…Q 7 DFBA 4. 5 K Q 6 Q 5 Q 4, D 2 D 1 1. 9 K DFBX Q 3, Q 2, Q 1 TAS TAN IP 1 IP 8 12 m RR 13 3 m UJ 13 A. Ballarino, 17 Nov. 2011
POWERING CONFIGURATION OF THE LHC –TODAY- INNER TRIPLETS Ø Nested circuits Ø One trim power converter on Q 1 DFBXA and DFBXB at P 1 DFBXE and DFBXF at P 5 N. of leads Rating (A) 10 120 14 600 4 7500 Itot 40 k. A D 1 at P 1 and P 5: resistive magnet Q 1, Q 2 and Q 3: four leads, each rated at 7500 A DC Corrector magnets: quadrupole, sextupole octupole (120 A/600 A) A. Ballarino, 17 Nov. 2011
POWERING CONFIGURATION OF THE HIGH LUMINOSITY –NEW- INNER TRIPLETS Ø Individual powering of each circuit ? Ø Nested powering, e. g. one main power converter plus current trimming on each magnet ? Ø Split powering, e. g. Q 1 in series with Q 2 a and Q 3 in series with Q 2 b ? Ø 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 ? Ø Time constant of the circuits and amount of stabilizer in the cables ? D 1 at P 1 and P 5: resistive magnet superconducting magnet, I 10 k. A Q 1, Q 2 and Q 3: four leads, each rated at at 7500 AA eight to four leads, each rated up to 15 k. A Corrector magnets: 120 A (dipole) and 600 A (sextupole) Itot 40 40 k. A > 100 k. A A. Ballarino, 17 Nov. 2011
Layout at Point 1 3. 6 m DFBL 4. 5 K Q 11, Q 10…Q 7 DFBA Q 6 Q 5 Q 4, D 2 D 1 I I 4. 5 K 1. 9 K DFBX Q 3, Q 2, Q 1 TAS TAN IP 1 IP 8 12 m RR 13 3 m UJ 13 A. Ballarino, 17 Nov. 2011
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
PM 54 DFBXE (RZ 54) DFBXF (UJ 56) PM 15 DFBXA (UJ 13) DFBXB (UJ 16) A. Ballarino, 17 Nov. 2011
2 100 k. A A. Ballarino, 17 Nov. 2011
A. Ballarino, 17 Nov. 2011
Conductors in Superconducting Links Mg. B 2 Tape : 3. 64 0. 65 mm 2 Mg. B 2: 12 % Cu : 15 % YBCO Tape : 4 0. 1 mm 2 YBCO: 1 -3 m Cu : 2 20 m Bi-2223 Tape : 4 0. 1 mm 2 YBCO: 1 -3 m Cu : 2 20 m A. Ballarino, 17 Nov. 2011
Conductors in Superconducting Links YBCO Mg. B 2 Ic(77 K, self field) 100 A A. Ballarino, 17 Nov. 2011
Minimum quench energy of superconductors 6 mm Nb-Ti cables used in LHC 6 k. A at 6 K Mg. B 2 cable 6 k. A at 20 K (> 12 k. A at 4. 5 K) Nb-Ti, Top = 5 K Tc= 6 K → MQE = 2. 63 m. J/cm 3 Tc = 7 K → MQE = 5. 26 m. J/cm 3 Tc = critical temperature Top = operating temperature MQE= Minimum Quench Energy A. Ballarino, 17 Nov. 2011
Cryogenics for Cold Powering System 20 K-50 K Tunnel A. Ballarino, 17 Nov. 2011
Where else in the LHC ? P 5 P 7 P 1 P 7 Underground Installation A. Ballarino, 17 Nov. 2011
Current Leads and Power Converters ~ 250 m ~ 0 m 5 2 Two links each about 500 m long 48 cables rated at 600 A per link Option also for P 3 A. Ballarino, 17 Nov. 2011
S. Weisz, J. Osborne A. Ballarino, 17 Nov. 2011
What do we have today ?
CERN Prototype Link 25 × 2 × 600 A (2 × 15 k. A) @ 35 K Mg. B 2 @ 65 K (YBCO and Bi-2223) Link for Point 7 2 kg/m 200 m. HTS/mcable = 40 A. Ballarino, 17 Nov. 2011
Integration of CERN Prototype Link in cryostat @ SOTON L=5 m A. Ballarino, 17 Nov. 2011
Test of 600 A HTS Cables Mg. B 2 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, 17 Nov. 2011
Test of CERN 600 A HTS Cables Mg. B 2 YBCO (CERN measurements) (SOTON measurements) Bi-2223 Top 600 A 15 K 55 K Proceedings of EUCAS 2011 A. Ballarino, 17 Nov. 2011
Cryostat for Link (20 m length) in SM-18 m 5. 1 R= A. Ballarino, 17 Nov. 2011
Cryostat for Link (20 m length) in SM-18 Semi-flexible line in SM-18 test station A. Ballarino, 17 Nov. 2011
High-current cable configurations Mg. B 2 round wire 27 cables 6000 A 48 cables 600 A Itot = 190 k. A @ 20 K ( 2 × 95 k. A) = 75 3 × 6 k. A = 15. 5 10 kg/m YBCO tape 900 m. HTS/mcable 24 × 6000 A 42 × 600 A Itot = 169 k. A & 20 K ( 2 × 84. 5 k. A) =70 A. Ballarino, Proceedings of ASC 2010 A. Ballarino, 17 Nov. 2011
High-current cable configurations Mg. B 2 round wire Φ = 62 mm 7 × 14 k. A, 7 × 3 k. A and 8 × 0. 6 k. A cables – Itot 120 k. A @ 30 K Development of round wire at Columbus Superconductors A. Ballarino, 17 Nov. 2011
CHALLENGES Ø Significant/unprecedented high-current long HTS cables (up to 15 k. A) Ø Complex multi-cable assembly Ø 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 Ø Complex system to be integrated in the LHC machine A. Ballarino, 17 Nov. 2011
OVERVIEW OF GLOBAL ACTIVITY Hi-Lumi FP 7 WP 6 Design study CERN activity Design study Task 1 Coordination Integration Task 2 Cryogenics Civil engineering Interfaces (mech, vacuum, electr) Vacuum Task 3 Electr. Transf. Cryostat Task 4 Energy Dep. Material SC cables/SC link CERN activity - Prototypes construction - Prototypes test - System design - Series specification - Series construction - Integration - Operation Cryostat of SC link Current leads Protection Fluka team
Timeline Test of horizontal links 2012 HTS Links in LHC P 1, P 5, P 7 Test of vertical links 2014 HTS Links in LHC Hi-Lumi P 1 and P 5 2018 2020 Civil Engineering Superconductor System production 2012 -2013 2018 -2019 2020 -2021 A. Ballarino, 17 Nov. 2011
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