1. CEA-CERN, WP7, 07072014, Pierre Manil, 1 CEA-CERN WP7 Mechanical studies of Rutherford cable @ Saclay: Pierre MANIL and François NUNIO @ CERN: Amalia BALLARINO 7 July 2014

2. CEA-CERN, WP7, 07072014, Pierre Manil, 2 Motivation and goals Low-temperature superconductors are pushed closer and closer to their mechanical limits in high field magnets. It becomes necessary to simulate local peak stresses and strains, especially with Nb 3 Sn conductors. Ultimate goal: integrated multi-scale modeling of the mechanics of Rutherford cable during operation (at the scale of the strand), correlated with experimental data (at the scale of the strand or the cable). In the 2014-2015 phase, WP7 will focus on realistic goals.

3. CEA-CERN, WP7, 07072014, Pierre Manil, 3 Background at Saclay WP7 is thought as an extension of an existing program at Irfu: CoCaSCOPE « Modélisation du comportement de câbles supraconducteurs à différentes échelles pour l'optimisation de leurs performances électriques ». Duration: 48 months from January 2013. Partners: WP7 will allow to collaborate with CERN in order to apply CoCaSCOPE modeling techniques to CERN cables (SMC, FRESCA2…) and to share experimental data.

4. CEA-CERN, WP7, 07072014, Pierre Manil, 4 Steps 1| Identification of several types of cable of interest 2| Identification of the strand behaviour law → dedicated experimental setup 3| Modeling of the cabling process → validation on the base of tomographic analysis 4| Geometrical reconstruction of insulated cables 5| Modeling of the cable under mechanical solliciation → comparison with experimental results on stacks

5. CEA-CERN, WP7, 07072014, Pierre Manil, 5 Modeling of the cabling process 1/2 Courtesy of François Nunio, Philippe Martinuzzi

6. CEA-CERN, WP7, 07072014, Pierre Manil, 6 Modeling of the cabling process 2/2 Courtesy of François Nunio, Philippe Martinuzzi

7. CEA-CERN, WP7, 07072014, Pierre Manil, 7 Geometrical reconstruction of cables Courtesy of François Nunio, Philippe Martinuzzi

8. CEA-CERN, WP7, 07072014, Pierre Manil, 8 Comparison with tomographic data Courtesy of François Nunio, Philippe Martinuzzi

9. CEA-CERN, WP7, 07072014, Pierre Manil, 9 Mechanical modeling On-going… Mechanical models will use the experimental behaviour law of strands Courtesy of François Nunio, Philippe Martinuzzi

10. CEA-CERN, WP7, 07072014, Pierre Manil, 10 Collaboration with CERN 1/2 Additional types of cables ► CERN will provide strand/cable samples ► CEA will simulate them Exchange of experimental data ► CEA will get tomographic data from its partners ► CEA will get mechanical behaviour laws from its partners ► CEA/CERN will share stack test results and other mechcanical test results ► CERN will share electric measurement results on the cable (TBC) 2015: possibility to fund 50% of a postdoc? Next steps (2016 → 2020…) to be discussed with CERN

11. CEA-CERN, WP7, 07072014, Pierre Manil, 11 Part of the effort will be shifted from 2014 to 2015 2015: possibility to fund 50% of a postdoc? Next steps (2016 → 2020…) to be discussed with CERN Collaboration with CERN 2/2

12. CEA-CERN, WP7, 07072014, Pierre Manil, 12 Some references… ITER : N. Mitchell, “Modeling of the effect of Nb 3 Sn strand composition on thermal strains and superconducting performance”, IEEE Trans. Applied Superconductivity, vol. 15, Issue 2, pp. 3572 - 3576, 2005 Padua, łódz : D.P. Boso, M. Lefik and B.A. Schrefler, “A multilevel homogenised model for superconducting strand thermomechanics”, Cryogenics, vol. 45, Issue 4, pp. 259-271, 2004. ECP : H. Bajas, D. Durville, D. Ciazynski, A. Devred, “Numerical Simulation of the Mechanical Behaviour of ITER Cable-in-conduit Conductors”, IEEE Trans. Applied Superconductivity, vol. 20, Issue 3, pp. 1467 - 1470, 2010 Berkeley : D. Arbelaez, S.O. Prestemon, P. Ferracin, A. Godeke, D.R. Dietderich, G. Sabbi, “Cable deformation simulation and a hierarchical framework for Nb3Sn Rutherford cables”, J. Phys.: Conf. Ser., vol. 234, Part 2, 2010 Fermilab : E. Barzi, G. Gallo, P. Neri, “FEM analysis of Nb-Sn Rutherford-type cables”, submitted for publication …