Radiation resistance of insulation systems for IR Triplets Acknowledgments: G. Ambrosio, F. Cerutti, S. Clément, L. S. Esposito, P. Ferracin, P. Fessia, R. Flukiger, R. Gauthier, M. Juchno, A. Mereghetti, N. Peray, J.-C. Perez, G. de Rijk, E. Todesco, Elvis Fornasiere | CERN, 26th February 2013 TE-MSC-MDT

Outline Structural requirements for MQXF based on expected dose Structural req + energy deposition Structural requirements for MQXF based on expected dose Measurement techniques for irradiated samples Experimental results on CTD-101K samples and CE-epoxy blend materials Experimental and FE simulations of the SBS Test on G10 Suggested Plan Measurement techniques CTD-101K + CE-epoxy results G10 SBS Test Plan End Elvis Fornasiere | CERN, 26th February 2013 TE-MSC-MDT 3

Beam screen shielding Beam screen with W absorbers at mid-planes Structural req + energy deposition Beam screen shielding 140 mm Nb3Sn Beam screen with W absorbers at mid-planes To go below 20 MGy one would need 2 mm BS + 9 mm W absorbers (105.6 mm residual aperture) Maximum thickness shielding for Q1-first half Q2A tailor-made Possible use of other materials for BS/CB under investigation Configurations Diameter aperture at mid-planes (mm) 3.7 mm BP + 7 mm W inserts 114.6 3.7 mm BP + 2 mm BS + 6 mm W absorbers* 111.6 * 0.5 mm clearance between BP and W Minimum aperture requested from optics is 116 mm With courtesy of F. Cerutti, L.S. Esposito on behalf of CERN FLUKA team [1]

Q1 Energy deposition Outline G10 SBS Test Plan End Structural req + energy deposition Measurement techniques CTD-101K + CE-epoxy results G10 SBS Test Plan Azimuthal energy deposition at Q1 peak End With courtesy of F. Cerutti, L.S. Esposito on behalf of CERN FLUKA team [2]+[3] Elvis Fornasiere | CERN, 26th February 2013 TE-MSC-MDT 5

Outline 150 mm Nb3Sn Shear stress G10 SBS Test Cool-down Structural req + energy deposition Measurement techniques Observation of Shear stress between turns and shear between inner and outer layers CTD-101K + CE-epoxy results G10 SBS Test Cool-down Max-gradient (155 T/m) 30-40 MPa shear t Plan 50-60 MPa shear singularity? End t t ~0 MPa shear With courtesy of M. Juchno and P. Ferracin [4] Elvis Fornasiere | CERN, 26th February 2013 TE-MSC-MDT 6

150 mm Nb3Sn Azimuthal stress Outline 150 mm Nb3Sn Azimuthal stress Structural req + energy deposition Measurement techniques CTD-101K + CE-epoxy results G10 SBS Test Cool-down Max-gradient (155 T/m) Plan Risk of tensile stress End 160 MPa compression stress With courtesy of M. Juchno and P. Ferracin [4] Elvis Fornasiere | CERN, 26th February 2013 TE-MSC-MDT 7

Detailed coil model status Outline Detailed coil model status Structural req + energy deposition “Rectangular” cable with 150um G10 insulation Cable material have similar properties as initial coil block (altered to spring model) High shear stress peaks at cable corners due to difference in thermal contraction Shear stress in coils up to ~30-40 MPa (cables and insulation around conductor in the vicinity of poles and copper blocks Possible next step: round “corners” or strand model with resin Measurement techniques CTD-101K + CE-epoxy results G10 SBS Test Plan End With courtesy of M. Juchno and P. Ferracin [4] Elvis Fornasiere | CERN, 26th February 2013 TE-MSC-MDT 8

Measurement techniques 1 Outline Measurement techniques 1 Structural req + energy deposition Test Nb 1 2 3 4 Name Flexural test Ultimate Tensile Test (UTS) Mode I: intralaminar crack opening Mode II: intralaminar shear mode Diagram Remarks Recommended by IEC. Most radiation-sensitive property for thermoset. Done at CERN for yellow books. Tests used for radiation effects on insulators for superconducting fusion magnets by the ATI, Vienna. In order to load the anisotropic FRPs in mode I as well as in mode II under their weakest condition, the fiber orientation with the lower fiber content was chosen to be perpendicular to the notches of the specimens. Measurement techniques CTD-101K + CE-epoxy results G10 SBS Test Plan End Elvis Fornasiere | CERN, 26th February 2013 TE-MSC-MDT 9

Measurement techniques 2 Outline Measurement techniques 2 Structural req + energy deposition Test Nb 5 6 7 Name Short Beam Shear (SBS). Interlaminar Shear/compression test 10° off-axis tensile test Diagram Remarks SBS: interlaminar strength. Other tests were done: double-lap-shear (DLS) test method, cycling test, etc. (not presented here). 10° off-axis tensile test is normally used for intralaminar shear strength Measurement techniques CTD-101K + CE-epoxy results G10 SBS Test Plan End Elvis Fornasiere | CERN, 26th February 2013 TE-MSC-MDT 10

Short-beam-shear test Outline ATI Vienna Facility 1 Structural req + energy deposition MTS 810 test facility Short-beam-shear test Measurement techniques CTD-101K + CE-epoxy results 5 cm G10 SBS Test 10 cm Plan 23 mm 6.4 – 6.5 mm End Sample thickness should be 3 mm, preferably 4 mm. At least 10 samples are needed for one test. In case of a wrapped insulation, the tests should be carried out parallel and perpendicular to the winding direction (10 + 10 samples). Approximately 90 shear samples can be irradiated in one run. With the courtesy of R. Prokopec [32] Elvis Fornasiere | CERN, 26th February 2013 TE-MSC-MDT 11

ATI Vienna Facility 2 Outline Tensile tests G10 SBS Test Plan End Structural req + energy deposition Tensile test specimen geometries Tensile tests Static: with and without strain recording Dynamic: load controlled Measurement techniques 10 10 20 At least 5 samples are needed for static tests and additional 20 samples for stress lifetime curves. 20 samples can be irradiated in one run (for 4 mm sample thickness). CTD-101K + CE-epoxy results G10 SBS Test 70 140 Plan ATI d-ASTM End Dose rate: 40 MGy in 5 open days 1 Container = 1 dose level Costs: 50 MGy = 16 k€ per container + staff ASTM With the courtesy of R. Prokopec [32] Elvis Fornasiere | CERN, 26th February 2013 TE-MSC-MDT 12

Relative mechanical properties for CTD-101K Outline Relative mechanical properties for CTD-101K Structural req + energy deposition Measurement techniques 30% degradation at 50 MGy ILSS0 ≈ 120 MPa CTD-101K + CE-epoxy results 70% degradation at 90 MGy Shear strength and degradation with irradiation is the most sensitive property G10 SBS Test 95% degradation at 160 MGy Plan End SBS test gives «apparent ILSS» UTS: 35% reduction at 180 Mgy from UTS0 ~ 1050 MPa Compressive strength = 1080 MPa at 160 Mgy (Loss 20%) Fracture Resistance GIC: 66% reduction at 230 MGy [29]+[30]+[31] Elvis Fornasiere | CERN, 26th February 2013 TE-MSC-MDT 13

Shear/compressive properties of CTD-101K Outline Shear/compressive properties of CTD-101K Structural req + energy deposition Measurement techniques Shear/compression failure envelope Shear strength increases with angle till 84°, then drops Compression prevents shear failure On vertical plane (at peak dose location), compression is huge and shear stress is small  Almost pure compression state CTD-101K + CE-epoxy results G10 SBS Test Plan 45° shear/compression test to characterize both types of heat treatment (14% reduction) No significant difference in mechanical properties between for specimen with and without heat treatment Not possible to compare interlaminar shear properties after 700°C heat treatment using SBS test (tensile mode failure)  UTS of fibers significantly damaged End [29]+[30]+[31]+[37]+[38]+[39] Elvis Fornasiere | CERN, 26th February 2013 TE-MSC-MDT 14

FE studies on Shear/Compression test Outline FE studies on Shear/Compression test Structural req + energy deposition Comparison analytical vs numerical investigations shows inhomogeneous and tri-axial stress state. Considerable thermal stresses arise from cooling to cryogenic temperatures (not evaluated by analytical considerations) Failure of the specimens mainly takes place at the interface (influence of thermal stresses) The reliability of the test method is questionable if the specimen fractures at the interface.  Strong dependency of surface conditions (arbitrary circumstances) Irradiation problem: high activation of steel plates Measurement techniques CTD-101K + CE-epoxy results G10 SBS Test Plan End [37]+[41] Elvis Fornasiere | CERN, 26th February 2013 TE-MSC-MDT 15

Mechanical properties for CE-epoxy blend Outline Mechanical properties for CE-epoxy blend Structural req + energy deposition Measurement techniques CTD-101K + CE-epoxy results G10 SBS Test Plan End Cyanate ester (AroCy-L10) [32+[33]+[34] Elvis Fornasiere | CERN, 26th February 2013 TE-MSC-MDT 16

G10 SBS experimental results Outline G10 SBS experimental results Structural req + energy deposition   Nb of specimen L (mm) b (mm) t (mm) l (mm) l/t Specimens A 5 24 10 4 12 3 Specimens B 16 Specimens C 42 28 7 Specimens D 6 Measurement techniques CTD-101K + CE-epoxy results G10 SBS Test Plan End SBS [MPa] FSBS_1 FSBS_2 FSBS_3 FSBS_4 FSBS_5 Average Standard deviation Coefficient of variation % Series A 54.80 58.03 55.87 55.37 56.77 56.17 1.27 2.26 Series B 53.50 54.22 52.14 48.32 51.68 51.97 2.28 4.39 Series C 38.17 36.30 35.84 36.11 33.54 35.99 1.65 4.59 Series D 54.91 56.28 55.86 55.04 54.86 55.39 0.64 1.16 With the courtesy of A. Gerardin (EDMS N° 1259235) + [40] Elvis Fornasiere | CERN, 26th February 2013 TE-MSC-MDT 17

Outline FE studies on SBS test Structural req + energy deposition Measurement techniques f-factor = 1 inside the specimens  the stress is equal to the shear stress obtained from an analytical 2D solution The real “ILSSs” are higher than the experimental results CTD-101K + CE-epoxy results G10 SBS Test Plan End [36] Elvis Fornasiere | CERN, 26th February 2013 TE-MSC-MDT 18

G10 SBS FE results Outline G10 SBS Test Plan End Structural req + energy deposition Measurement techniques CTD-101K + CE-epoxy results G10 SBS Test Plan Shear at D (MPa) Shear at F (MPa) Sigma x at F Inside (MPa) Sigma z at F Inside (MPa) Exp. ILSS SBS (MPa) Inside Outside f-factor Series A 56.17 55.61 67.97 1.22 129.79 140.24 374.48 -127.01 Series B 51.97 51.05 63.63 1.25 125.01 130.38 454.98 -122.71 Series C 35.99 33.99 43.84 1.29 88.36 82.41 509.98 -86.82 Series D 55.39 55.38 64.83 1.17 133.19 147.61 494.08 -130.83 End Contrainte de rupture à la flexion, <= 10 mm perpendiculairement aux strates, sens longitudinal : > 350 N/mm2 Elvis Fornasiere | CERN, 26th February 2013 TE-MSC-MDT 19

Outline G10 SBS Test Structural req + energy deposition Measurement techniques CTD-101K + CE-epoxy results G10 SBS Test Elvis Fornasiere | CERN, 26th February 2013 TE-MSC-MDT 20

Suggested plan Outline Structural req + energy deposition Internal test campaign prior to irradiation campaign (unirradiated fibers) SBS test of heat treated fibers with 3 resins (CTD-101K, CE/epoxy blend, MY750) Resin with 1)virgin fiber, 2) 50h @700°C fiber, 3) 50h @700°C ht fiber + ceramic binder + 4) 50h @700°C ht fiber + PVA 10° off axis-test as support of SBS test Shear/compression test of the system [cable + insulation] Irradiation campaign (to be discussed) What is the maximum dose level (20 MGy)? SBS – Interlaminar shear test (qualitative) Shear/compression test of the system [cable + insulation] (Quantitative) Measurement techniques CTD-101K + CE-epoxy results G10 SBS Test Plan End CTD-101K MY750 CE Virgin fibers Fibers after reaction Fibers after reaction and ceramic binder SBS + Tensile +/- 10° + shear/compression Elvis Fornasiere | CERN, 26th February 2013 TE-MSC-MDT 21

Thanks for your attention Questions? Outline Structural req + energy deposition Measurement techniques CTD-101K + CE-epoxy results Thanks for your attention Questions? G10 SBS Test Plan End Elvis Fornasiere | CERN, 26th February 2013 TE-MSC-MDT 22

150 mm Nb3Sn Radial stress With courtesy of M. Juchno and P. Ferracin [4] Elvis Fornasiere | CERN, 26th February 2013 TE-MSC-MDT 24

References F. Cerutti, L.S. Esposito on behalf of CERN Fluka team, “Shielding the 140 option”, Hi-Lumi LHC WP10, CERN, 26 July 2012. F. Cerutti, L.S. Esposito on behalf of CERN Fluka team, “First estimates of energy deposition for the new inner triplet”, Hi-Lumi LHC WP10, CERN, 7 June 2012. L.S. Esposito, private communication, CERN, 25.02.2013. M. Juchno, private communication, CERN, 25.02.2013. C. Barrère, D. Dal Maso, Résines époxy réticulées par des polyamines: structure et propriétés, Revue de L’Institut Français du Pétrole, Vol. 52, N° 3, Mai-Juin 1997 P. Bardonnet, Résines époxydes (EP) – Composants et propriétés, Doc. A 3 465, Techniques de l’Ingénieur, 2012 T. Devanne, Vieillissement radiochimique d’un réseau époxyde, Thèse N° 2003-05, E.N.S.A.M, 16 Mai 2003 D.W. Clegg, A. A. Collyer, Irradiation effects on polymers, Elsevier Science Publishers LTD, London, 1991 A. Idesaki, A. Shimada, N. Morishita, M. Sugimoto, M. Yoshikawa, Evalutation of Radiation Resistance for Organic Materials Used in Atomic Energy-related Facilities, Radiation Effects in Super Conducting Magnet Materials (RESMM’12), Fermilab, February 13-15,2012 D. Reed, Radiation Tolerance of Resins, Rad-Hard Insulation Workshop, Fermilab, April 20, 2007 H. Schönbacher, A. Stolarz-Izycka, Compilation of radiation damage test data – Part II: Thermosetting and thermoplastic resins, CERN 79-08, Geneva, 1979 M. H. Van de Voorde, Effects of radiation on materials and components, CERN 70-5, Geneva, 1970 M. H. Van de Voorde, Action des radiations ionisantes sur les résines époxydes, CERN 70-10, Geneva, 1970 M. Tavlet, A. Fontaine and H. Schönbacher, “Compilation of radiation damage test data, pt.2: Thermoset and thermoplastic resins, composite materials”, CERN-98-01, Geneva : CERN, 1998. - 173 p. 26/02/2013 E. Fornasiere

References International Electrotechnical Commission, Geneva, Publication No. 544: Guide for determining the effects of ionizing radiation on insulating materials, Part I: Radiation interaction, Ref. 544–1 (1977); Part 2: Procedures for irradiation, Ref. 544–2 (1979); Part 3: Test procedures for permanent effects, Ref. 544–3 (1979); Part 4: Classification system for service in radiation environments, Ref. 544–4 (1985). D.C. Phillips et al., The selection and properties of epoxide resins used for the insulation of magnet systems in radiation enviroments, CERN 81–05 (1981). H. Schönbacher, B. Szeless and M. Tavlet, “Results of radiation tests at cryogenic temperature on some selected organic materials for the LHC”, CERN 96-05, Geneva, 1996 G. Lipták et al., “Radiation tests on selected electrical insulating materials for high-power and highvoltage application”, CERN 85–02, Geneva, 1985. H. W. Weber et al., “Low temperature neutron and gamma irradiation of glass fiber reinforced epoxies”, Journal of Nuclear Materials 115 (1983) 11-15 K. Humer et al., “Radiation effects on insulators for superconducting fusion magnets”, Cryogenics 35 (1995) 871-882 René Flükiger, Gijs de Rijk, “Review of WAMSDO 2011 Workshop: Superconductors in LHC Upgrade (HiLumi LHC)”, RESMM’12, Fermilab, 13-15.02.2012 Ezio Todesco, “ High Luminosity LHC: Magnets”, Applied Superconductivity Conference, Portland, 9th October 2012 P. Ferracin, “MQXF coil cross-section status”, HiLumi WP3 Video-meeting, 28 August, 2012 P. Fessia, “The CERN magnet program and the conductor needs”, LTHFS Worhshop, Napa Valley – 5th to 7th November 2012 25/02/2013 E. Fornasiere

References K. Humer et al., “Tensile and shear fracture behavior of fiber reinforced plastics at 77 K irradiated by various radiation sources”, Adv. Cryog. Eng. 40 (1993) K. Humer et al., “Low temperature tensile and fracture mechanical strength in mode I and mode II of fiber reinforced plastics following various irradiation conditions”, Fusion Technology 1994 K. Humer et al., “Tensile and fracture behavior in mode I and mode II of fiber reinforced plastics following reactor irradiation”, Advances in Cryogenic Engineering (1996), Vol. 42 K. Humer et al., “Low-temperature interlaminar shear strength of reactor irradiated glass-fibre-reinforced laminates”, Cryogenics 36 (1996) 611-617 Composite Technology Development, Inc. “CTD-101 and CTD-101K Epoxy Resin System”, Datasheet, 2003. Composite Technology Development, Inc. “CTD-101K Epoxy Resin System”, Datasheet, 2003. Composite Technology Development, Inc. “CTD-101K Epoxy Resin System”, Datasheet, 2012. N. A. Munshi, J. K. Walsh, M. W. Hooker, H. K. Babcock, “Radiation Resistant Electrical Insulation Qualified for ITER TF Coils”, Applied Supeconductivity Conference, Portland (OR), October 2012. Composite Technology Development, Inc. “CTD-400 Series Cyanate Ester Resins for RTM High Performance, Eady Processing”, Datasheet, 2002. Composite Technology Development, Inc. “Cyanate Ester-based Insulations Summary Data Sheet”, Datasheet. R. Prokopec, “Mechanical tests on radiation resistant insulation materials”, PPT Presentation, 19.12.2012 D.H. Pahr, F.G. Rammerstorfer, P. Rosenkranz, K. Humer, H.W. Weber, “A study of short-beam-shear and double-lap-shear specimens of glass fabric/epoxy composites”, Composites: Part B 33 (2002) 125-132. D.H. Pahr, H.J. Böhm, K. Humer, H. W. Weber, “Analytical and finite element investigations of shear/compression test fixtures”, Cryogenics 45 (2005), 606-616. 26/02/2013 E. Fornasiere

References P.E. Fabian, J. B. Schutz, C. S. Hazelton, R. P. Reed, “Properties of candidate ITER Vacuum Impregnation Insulation Systems”, Advances in Cryogenic Engineering, Vol. 40, New York, 1994 P.E. Fabian, R.P. Reed, J.B. Schutz, T.S. Bauer-McDaniel, “Shear/compressive properties of candidate ITER inuslation systems at low temperatures”, Cryogenics 35 (1995) 689-692 R. P. Reed, J. B. Darr, J. B. Schutz, “Short-Beam Shear Testing of candidate magnet inulators”, Cryogenics (1992), Vol. 32 ICMC Supplement H. Weber, private communication, Email exchange, 19.02.2013. 26/02/2013 E. Fornasiere