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MQXF Coil Structural Design CriteriaPreliminary outline/draft for comments

11/8/2017

Contents1 Background............................................................................................................................ 1

2 LARP program experience.....................................................................................................1

2.1 Performance studies as a function of pre-load and transverse coil stress in TQS03........1

2.2 Cycling tests in Technology Quadrupoles.......................................................................3

2.3 Performance studies as a function of pre-load and transverse coil stress in HQ02..........3

2.4 Dependence of stress limits on initial conditions: HQ01 vs HQ02..................................4

2.5 Studies of Axial coil stress in Technology Quadrupoles.................................................4

3 LARP criteria for coil pre-load and maximum stress..............................................................4

4 MQXF Mechanical Analysis..................................................................................................5

5 References.............................................................................................................................. 5

1 Background

Nb3Sn strain dependence models and experimental validation Relevant design characteristics of Nb3Sn accelerator magnets affecting the stress limits

Coil environment: Rutherford cable, heat treatment, epoxy impregnation Pre-load requirements to prevent motion under Lorentz forces Coil stress evolution at assembly, cool-down and powering

Potential mechanisms limiting magnet performance under high stress

Permanent degradation in high field pole region (due to pre-load) Permanent or reversible degradation in high field mid-plane region due to combination of

pre-load and Lorentz forces during excitation to high field Conductor damage reducing stability limits in low field mid-plane region

2 LARP program experience

2.1 Performance studies as a function of pre-load and transverse coil stress in TQS03

Four tests performed in TQS03 models with different pre-load

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Increasing pre-load in a/b/c (pole ave.120/160/200 MPa) gives more stable but lower plateau (93/91/88%)

TQS03c achieved 88% of the SSL based on extracted strands under (calculated) peak coil stress of 260 MPa (4.5K, 0T/m) and 240 MPa (4.5K, 88% SSL).

-260-240-220-200-180-160-140-120-100-80-60-40-20

0Ti pole L1 pole L1 mp L2 pole L2 mp

Azi

mut

hal s

tres

s (M

Pa)

TQS03aTQS03bTQS03cTQS03d

-140

-120

-100

-80

-60

-40

-20

0Ti pole L1 pole L1 mp L2 pole L2 mp

Azi

mut

hal s

tres

s (M

Pa)

TQS03aTQS03bTQS03cTQS03d

Good performance in a broad range of coil stress provides margin to accommodate variations due to fabrication tolerances

TQS03d with lower pre-load does not recover initial level: degradation is permanent

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2.2 Cycling tests in Technology Quadrupoles

Cycling test on TQS03d: performed 1000 cycles with control quenches every ~150 cycles No change in mechanical parameters or quench levels

2.3 Performance studies as a function of pre-load and transverse coil stress in HQ02

HQ02a/a2: o Peak coil stress: 189 MPa (pole, 0 T/m); 166 MPa (mid-plane, 180 T/m) o Reaches 80% SSL with all new coils in few/no quenches (4.5K and 1.9K) o Slow training above ~85% SSL (30 A/quench on average)o No degradation: reached 98% SSL at 4.5K

HQ02b: o Peak coil stress: 205 MPa (pole, 0 T/m); 189 T/m (mid-plane, 195 T/m)o Significant improvement of training speed: from 30 A/quench to 230 A/quench

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2.4 Dependence of stress limits on initial conditions: HQ01 vs HQ02

Premature quenches observed at both the pole and mid-plane in HQ01d under moderate stress levels

Pole quenches and strain gauge data indicate insufficient pre-load Mid-plane quenches indicate excessive pre-load Narrow design and assembly window

Safe pre-load window was significantly expanded after changes in axial and transverse conditions during reaction

2.5 Studies of Axial coil stress in Technology Quadrupoles

Localized quenches at pole gaps with bronze poles in TQS01 Analysis shows large spike in coil axial tension at gap locations. Longitudinal strain

estimated at Change of pole material from Al-bronze to Ti removed axial tension and gap quenches

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3 LARP criteria for coil pre-load and maximum stress

Ensure sufficient pre-load to ensure contact up to target gradiento Localized tension up to ~25 MPa is acceptable

Maximum stress in the pole region at cold should not exceed [200] MPa Maximum stress in the mid-plane region at target gradient should not exceed [200] MPa

4 MQXF Mechanical Analysis

Pre-load strategy: maintain contact between the coils and poles pieces at all stages of assembly, cool-down and powering, up to a gradient of 140 T/m.

Coil stress criteria: keep below 200 MPa at cold, from 0 to 140 T/m 2D analysis: the maximum σθ in coil is 124 MPa at RT with the stainless steel vessel welded

outside the structure, and -177 MPa after cool-down 3D analysis: The coil reaches a maximum compression of −129 MPa during room

temperature bladder operation, −192 MPa in the pole region at 1.9 K, and −146 MPa on the mid-plane with Lorentz forces at 140 T/m.

4.2 K

140 T/m

5 References

1. US HL-LHC Accelerator Upgrade Project, Q1/Q3 Cryo-Assemblies Conceptual Design Report, US-HiLumi-doc-140, July 17, 2017

2. G. Vallone et al., “Mechanical Performance of Short Models for MQXF, the Nb3Sn Low-β Quadrupole for the Hi-Lumi LHC”, IEEE Transactions on Applied Superconductivity Vol. 27, No. 4 (2017). Art. No. 4002906.

3. G. Chlachidze; G. Ambrosio; M. Anerella; R. Bossert; E. Cavanna; D. Cheng; D. Dietderich; J. DiMarco; H. Felice; P. Ferracin; A. Ghosh; P. Grosclaude; M. Guinchard; R. Hafalia; E. Holik; S. Izquierdo Bermudez; S. Krave; M. Marchevsky; A. Nobrega; D. Orris; H. Pan; J.C. Perez; S. Prestemon; E. Ravaioli; G. Sabbi; T. Salmi; J. Schmalzle; S. Stoynev; T. Strauss; C. Sylvester; M. Tartaglia; E. Todesco; G. Vallone; G. Velev; P. Wanderer; X. Wang; M. Yu, “Performance of the First Short Model 150-mm-Aperture Nb3Sn Quadrupole MQXFS for the High-Luminosity LHC Upgrade”, IEEE Transactions on Applied Superconductivity Vol. 27, No. 4 (2017). Art. No. 4000205, DOI: 10.1109/TASC.2016.2629001

4. J. DiMarco, G. Ambrosio, M. Anerella, H. Bajas, G. Chlachidze, F. Borgnolutti, R. Bossert, D. Cheng, D. Dietderich, H. Felice, T. Holik, H. Pan, P. Ferracin, A. Ghosh, A. Godeke, A. R. Hafalia, M. Marchevsky, D. Orris, E. Ravaioli, G. Sabbi, T. Salmi, J. Schmalzle, S. Stoynev, T. Strauss, C. Sylvester, M. Tartaglia, E.

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Todesco, P. Wanderer, X. Wang, M. Yu, “Test Results of the LARP Nb3Sn Quadrupole HQ03a”, IEEE Transactions on Applied Superconductivity Vol. 26, No. 4 (2016). Art. No. 4005105.

5. P. Ferracin, G. Ambrosio, M. Anerella, A. Ballarino, H. Bajas, M. Bajko, B. Bordini, R. Bossert, D. W. Cheng, D. R. Dietderich, G. Chlachidze, L. Cooley, H. Felice, A. Ghosh, R. Hafalia, E. Holik, S. Izquierdo Bermudez, P. Fessia, P. Grosclaude, M. Guinchard, M. Juchno, S. krave, F. Lackner, M. Marchevsky, V. Marinozzi, F. Nobrega, L. Oberli, H. Pan, J. C. Perez, H. Prin, J. Rysti, E. Rochepault, G. Sabbi, T. Salmi, J. Schmalzle, M. Sorbi, S. Sequeira Tavares, E. Todesco, P. Wanderer, X. Wang, M. Yu, “Development of MQXF: The Nb3Sn Low-B Quadrupole for HiLumi LHC”, IEEE Transactions on Applied Superconductivity Vol. 26, No. 4 (2016). Art. No. 4000207.

6. H. Pan et al., “Assembly tests of the first Nb3Sn low-β quadrupole short model for the Hi-Lumi LHC,” IEEE Trans. Appl. Supercond., vol. 26, no. 4, Jun. 2016, Art. no. 4001705.

7. M. Juchno et al., “Support structure design of the Nb3Sn quadrupole for the high luminosity LHC,” IEEE Trans. Appl. Supercond., vol. 25, no. 3, Jun. 2015, Art. no. 4001804H.

8. Bajas, G. Ambrosio, M. Anerella, M. Bajko, R. Bossert, L. Bottura, S. Caspi, D. Cheng, A. Chiuchiolo, G. Chlachidze, D. Dietderich, H. Felice, P. Ferracin, J. Feuvrier, A. Ghosh, C. Giloux, A. Godeke, R. Hafalia, M. Marchevsky, E. Ravaioli, G. Sabbi, T. Salmi, J. Schmalzle, E. Todesco, P. Wanderer, X. Wang, M. Yu, “Test Results of the LARP HQ02b Magnet at 1.9 K”, IEEE Transactions on Applied Superconductivity Vol. 25, No. 3, June 2015. Art. No. 4003306.

9. F. Borgnolutti, G. Ambrosio, R. Bossert, G. Chlachidze, D. Cheng, D. Dietderich, H. Felice, A. Godeke, R. Hafalia, M. Marchevsky, G. Sabbi, J. Schmalzle, P. Wanderer, M. Yu, “Fabrication of a Third Generation of Nb3Sn Coils for the LARP HQ03 Quadrupole Magnet”, IEEE Transactions on Applied Superconductivity Vol. 25, No. 3, June 2015. Art. No. 4002505.

10. G. Chlachidze, G. Ambrosio, M. Anerella, F. Borgnolutti, R. Bossert, S. Caspi, D.W. Cheng, D. Dietderich, H. Felice, P. Ferracin, A. Ghosh, A. Godeke, A.R. Hafalia, M. Marchevsky, D. Orris, P.K. Roy, G.L. Sabbi, T. Salmi, J. Schmalzle, C. Sylvester, M. Tartaglia, J. Tompkins, P. Wanderer, X.R. Wang, and A.V. Zlobin, "Performance of HQ02, an Optimized Version of the 120 mm Nb3Sn LARP Quadrupole", IEEE Transactions on Applied Superconductivity 24, (2014).

11. F. Borgnolutti, G. Ambrosio, R. Bossert, G. Chlachidze, D.W. Cheng, D.R. Dietderich, H. Felice, A. Godeke, A.R. Hafalia, M. Marchevsky, P.K. Roy, G.L. Sabbi, J. Schmalzle, P. Wanderer, and M. Yu, "Fabrication of a Second-Generation of Nb3Sn Coils for the LARP HQ02 Quadrupole Magnet", IEEE Transactions on Applied Superconductivity 24, (2014).

12. G. Sabbi, “Nb3Sn IR Quadrupoles for the High Luminosity LHC”, IEEE Transactions on Applied Superconductivity, Vol. 23, No. 3 (June 2013) 4000707

13. E. Todesco, H. Allain, G. Ambrosio, F. Borgnolutti, F. Cerutti, D. Dietderich, L. Esposito, H. Felice, P. Ferracin, G. Sabbi, P. Wanderer, R. VanWeelderen, Design Studies for the Low-Beta Quadrupoles for the LHC Luminosity Upgrade, IEEE Transactions on Applied Superconductivity, Vol. 23, No. 3 (June 2013) 4002405

14. H. Bajas, G. Ambrosio, M. Anerella, M. Bajko, R. Bossert, S. Caspi, A. Chiuchiolo, G. Chlachidze, D. Dietderich, O. Dunkel, H. Felice, P. Ferracin, J. Feuvrier, L. Fiscarelli, A. Ghosh, C. Giloux, A. Godeke, A. R. Hafalia, M. Marchevsky, S. Russenschuck, G. L. Sabbi, T. Salmi, J. Schmalzle, E. Todesco, P. Wanderer, X. Wang, M. Yu, Cold Test Results of the LARP HQ Nb3Sn Quadrupole Magnet at 1.9 K, IEEE Transactions on Applied Superconductivity, Vol. 23, No. 3 (June 2013) 4002606

15. A. Godeke, G. Chlachidze, D. Dietderich, A. Ghosh, M. Marchevsky, M. Mentink and G. Sabbi, A review of conductor performance for the LARP high-gradient quadrupole magnets, Supercond. Sci. Technol. 26 (2013) 095015.

16. P. Ferracin, G. Ambrosio, M. Anerella, R. Bossert, S. Caspi, G. Chlachidze, D. Cheng, D. Dietderich, H. Felice, A. Ghosh, R. Hafalia, J. Lizarazo, M. Marchevsky, J. Joseph, G. Sabbi, J. Schmalzle, P. Wanderer, X. Wang, A. Zlobin, “Mechanical Behavior of HQ01, a Nb3Sn Accelerator-Quality Quadrupole Magnet for the LHC Luminosity Upgrade”, IEEE Transactions on Applied Superconductivity, Volume: 22 , Issue: 3, 2012 (4901804)

17. M. Marchevsky, G. Ambrosio, B. Bingham, R. Bossert, S. Caspi, D. Cheng, G. Chlachidze, D. Dietderich, J. DiMarco, H. Felice, P. Ferracin, A. Ghosh, R. Hafalia, J. Joseph, J. Lizarazo, G. Sabbi, J. Schmalzle, P. Wanderer, X. Wang, A. Zlobin, “Quench Performance of HQ01, a 120 mm Bore LARP Quadrupole for the LHC Upgrade”, IEEE Transactions on Applied Superconductivity, Volume: 22 , Issue: 3, 2012 (4702005)

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18. H. Felice, G. Ambrosio, M. Anerella, D. Bocian, R. Bossert, B. Collins, D. Cheng, G. Chlachidze, D. Dietderich, P. Ferracin, A. Godeke, A. Ghosh, R. Hafalia, J. Joseph, J. Krishnan, M. Marchevsky, G. Sabbi, J. Schmalzle, P. Wanderer, X. Wang, A. Zlobin, “Impact of Coil Compaction on Nb3Sn LARP HQ Magnet”, IEEE Transactions on Applied Superconductivity, Volume: 22 , Issue: 3, 2012 (4001904)

19. H Felice, G Ambrosio, M Bajko, E Barzi, B Bordini, R Bossert, S Caspi, D Dietderich, P Ferracin, J Feuvrier, A Ghosh, A Godeke, J Lizarazo, L Rossi, G Sabbi, P Wanderer, X Wang, A V Zlobin, “Test results of TQS03: a LARP shell-based Nb3Sn quadrupole using RRP 108/127 conductor” J. Phys.: Conf. Ser, 032002, 2010, 234. SMP-201007-2A, LBNL-3891E

20. P. Ferracin, G. Ambrosio, M. Anerella, B. Bingham, R. Bossert, S. Caspi, D. W. Cheng, G. Chlachidze, H. Felice, A. R. Hafalia, W. Mumper, F. Nobrega, S. Prestemon, G. L. Sabbi, J. Schmalzle, C. Sylvester, M. Tartaglia, P. Wanderer, and A. V. Zlobin, “Mechanical Performance of the LARP Nb3Sn Quadrupole Magnet LQS01”, IEEE Trans. Appl. Supercond., vol. 21, no. 3, June 2011, pp. 1683-1687.

21. S. Caspi, G. Ambrosio, M. Anerella, E. Barzi, B. Bingham, R. Bossert, D. W. Cheng, G. Chlachidze, D. R. Dietderich, H. Felice, P. Ferracin, A. Ghosh, A. R. Hafalia, C. R. Hannaford, J. Joseph, V. V. Kashikhin, G. L. Sabbi, J. Schmalzle, P. Wanderer, W. Xiaorong, and A. V. Zlobin, “Test Results of 15 T Nb3Sn Quadrupole Magnet HQ01 with a 120 mm Bore for the LHC Luminosity Upgrade”, IEEE Trans. Appl. Supercond., vol. 21, no. 3, June 2011, pp. 1854-1857.

22. H. Felice, M. Bajko, B. Bingham, B. Bordini, L. Bottura, S. Caspi, G. De Rijk, D. Dietderich, P. Ferracin, C. Giloux, A. Godeke, R. Hafalia, A. Milanese, L. Rossi, and G. L. Sabbi, “Performance of a Nb3Sn Quadrupole Under High Stress”, IEEE Trans. Appl. Supercond., vol. 21, no. 3, June 2011, pp. 1849-1853.

23. P. Ferracin, B. Bingham, S. Caspi, D.W. Cheng, D.R. Dietderich, H. Felice, A. Godeke, A.R. Hafalia, C.R. Hannaford, J. Joseph, A.F. Lietzke, J. Lizarazo, G.L. Sabbi, F. Trilluad, X. Wang, “Assembly and Test of HD2, a 36 mm Bore High Field Nb3Sn Dipole Magnet”, Presented to the 2008 Applied Superconductivity Conference, ASC08, Chicago, IL, USA, August 17 - 22, 2008. Accepted for publication in the IEEE Transactions on Applied Superconductivity.

24. H. Felice, S. Caspi, D. Cheng, D. Dietderich, P. Ferracin, R. Hafalia, R. Hannaford, A.F. Lietzke, G.L. Sabbi, M. Anerrela, P. Wanderer, G. Ambrosio, R. Bossert, V.V. Kashikhin, A.V. Zlobin, “Design of HQ - a High Field Large Bore Nb3Sn Quadrupole Magnet for LARP”, Presented to the 2008 Applied Superconductivity Conference, ASC08, Chicago, IL, USA, August 17 - 22, 2008. Accepted for publication in the IEEE Transactions on Applied Superconductivity.

25. S. Caspi, B. Bingham, H. Felice, P. Ferracin, R. Hafalia, A. Lietzke, J. Lizarazo, G.L. Sabbi, X. Wang, M. Bajko, M. Karppinen, J.C. Perez, A. Siemko, E. Todesco, “Assembly and Test of the Nb3Sn quadrupole magnet TQS02b”, Presented to the 2008 Applied Superconductivity Conference, ASC08, Chicago, IL, USA, August 17 - 22, 2008. Accepted for publication in the IEEE Transactions on Applied Superconductivity.

26. A. Godeke, D. Arbelaez, D.R. Dietderich, A. Ghosh, S. O. Prestemon, G. Sabbi, F. Trillaud, H. W. Weijers “Transverse Pressure Sensitivity Measurements on LARP High Current Niobium-Tin Rutherford Cables” Presented to the 2009 Cryogenic Engineering Conference and International Cryogenic Material Conference, CEC-ICMC, Tucson, Arizona, USA, June 28-July 2, 2009.

27. P. Ferracin, G. Ambrosio, B. Bordini, S. Caspi, D. R. Dietderich, H. Felice, A. R. Hafalia, C. R. Hannaford, J. Lizarazo, A. F. Lietzke, A. D. McInturff, G. L. Sabbi, J. D. DiMarco, M. Tartaglia, and P. Vedrine, “Effect of Axial Loading on Quench Performance in Nb3Sn Magnets”, IEEE Trans. Appl. Supercond., vol. 18, no. 2, June 2008, 285-288. LBNL-1007E

28. H. Felice, S. Caspi, P. Ferracin, V. V. Kashikhin, I. Novitski, G. L. Sabbi, and A. V. Zlobin, “Magnetic and Mechanical Analysis of the HQ Model Quadrupole Designs for LARP”, IEEE Trans. Appl. Supercond., vol. 18, no. 2, June 2008, 281-284. LBNL-1010E

29. S. Caspi, G. Ambrosio, A. N. Andreev, E. Barzi, R. Bossert, D. R. Dietderich, P. Ferracin, A. Ghosh, A. R. Hafalia, V. V. Kashikhin, A. F. Lietzke, I. Novitski, G. L. Sabbi, and A. V. Zlobin, “Test and Analysis of Technology Quadrupole Shell (TQS) Magnet Models for LARP”, IEEE Trans. Appl. Supercond., vol. 18, no. 2, June 2008, 179-183. LBNL-1050E

30. H. Felice, S. Caspi, D. R. Dietderich, P. Ferracin, S. A. Gourlay, A. R. Hafalia, A. F. Lietzke, A. Mailfert, G.L. Sabbi, and P. Vedrine, “Design and Test of a Nb3Sn Subscale Dipole Magnet for Training Studies”, IEEE Trans. Appl. Supercond., vol. 17, no. 2, June 2007,1144-1148.(2007)..

31. P. Ferracin, S. E. Bartlett, S. Caspi, D. R. Dietderich, S. A. Gourlay, A. R. Hafalia, C. R. Hannaford, A. F. Lietzke, S. Mattafirri, A. D. McInturff, and G. L. Sabbi, “Mechanical design of HD2, a 15 T Nb 3Sn dipole magnet with a 35 mm bore”, IEEE Trans. Appl. Supercond., vol. 16, no. 2, June 2006, 378-381. (2006).

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32. A. F. Lietzke, S. E. Bartlett, P. A. Bish, S. Caspi, D. R. Dietderich , P. Ferracin, S. A. Gourlay, C. R. Hannaford, A. R. Hafalia, W. G. Lau, N. Liggins, S. Mattafirri, A. D. McInturff, M. Nyman, G. Sabbi, R. M. Scanlan, and J. Swanson, “Test results of HD1b, an upgraded 16 T Nb3Sn dipole magnet”, IEEE Trans. Appl. Supercond., vol. 15, no. 2, June 2005, 1123-1127, also in LBNL-54894, April 2005.(2005).

33. P. Ferracin, S. E. Bartlett, S. Caspi, D. R. Dietderich, S. A. Gourlay, C. R. Hannaford, A. R. Hafalia, A. F. Lietzke, S. Mattafirri, and G. Sabbi, “Mechanical analysis of the Nb3Sn dipole magnet HD1”, IEEE Trans. Appl. Supercond., vol. 15, no. 2, June 2005, 1119-1122, also in LBNL-54887, April 2005.(2005).

34.35.