1. CARE08, Dec 4 2008, G. de Rijk, Summary report on NED activities 1 Summary Report on NED Activities Gijs de Rijk (CERN) on behalf of the NED collaboration 4 th December 2008

2. CARE08, Dec 4 2008, G. de Rijk, Summary report on NED activities Outline Main objectives of NED NED structure and participants Achievements of the NED Work Packages NED continuity : Short Model Coil NED successor EuCARD - High Field Magnets 2

3. CARE08, Dec 4 2008, G. de Rijk, Summary report on NED activities Main objectives of NED From the NED proposal: The main Objectives 1.to promote the development of high performance Nb 3 Sn wire in collaboration with European industry 2.to develop a parametric design of a large-aperture (up to 88 mm), high-field (up to 15 T) Nb 3 Sn dipole magnet 3.to execute a limited scientific program on heat transfer studies and insulation development, both directly related to Nb 3 Sn conductor technology. The program should lay the ground to the realisation of a Nb 3 Sn dipole magnet model that could push the technology well beyond present LHC limits 3

4. CARE08, Dec 4 2008, G. de Rijk, Summary report on NED activities Outline Main objectives of NED NED structure and participants Achievements of the NED Work Packages NED continuity : Short Model Coil NED successor EuCARD - High Field Magnets 4

5. CARE08, Dec 4 2008, G. de Rijk, Summary report on NED activities 5 NED structure and participants NED Structure The NED JRA has been articulated around four Work Packages and one Working Group 1 Management & Communication (M&C), 2 Thermal Studies and Quench Protection (TSQP), 3 Conductor Development (CD), 4 Insulation Development and Implementation (IDI), 5 Magnet Design and Optimization (MDO) Working Group. It involves 7 institutes (8 laboratories) Total budget: ~2 M€; EU grant: 979 k€ over ~3 (planned) years.

6. CARE08, Dec 4 2008, G. de Rijk, Summary report on NED activities 6 NED structure and participants NED Participants Beneficiaries: STFC-RAL (UK): E. Baynham, S. Canfer, G. Ellwood, J. Greenhalgh, P. Loveridge, J. Rochford CEA/DSM/Irfu (F): F. Rondeaux, B. Baudouy, A. Devred, H. Felice, M. Durante, P. Manil, J. Polinski, L. Quettier, J-M. Rifflet, P. Vedrine CERN: T. Boutboul, A. Devred, P. Fessia, D. Leroy, L. Oberli, F. Regis, D. Richter, G. de Rijk, L. Rossi, C. Scheuerlein, N. Schwerg, S. Sgobba, C. Vollinger, R. Van Weelderen INFN/Milano-LASA (I): F. Broggi, M. Sorbi, D. Pedrini, G. Volpini INFN/Genova (I): P. Fabbricatore, S. Farinon, M. Greco Twente University (NL): A. den Ouden Wroclaw Politechnic (PL): M. Chorowski, J. Fydrych, S. Pietrowicz, J. Polinski Associated institutes: CIEMAT (E): S. Sanz, F. Toral Fernandez Geneva University (CH): R. Flukiger, B. Seeber

7. CARE08, Dec 4 2008, G. de Rijk, Summary report on NED activities Outline Main objectives of NED NED structure and participants Achievements of the NED Work Packages NED continuity : Short Model Coil NED successor EuCARD - High Field Magnets 7

8. CARE08, Dec 4 2008, G. de Rijk, Summary report on NED activities 8 Work Package 2: Thermal Studies and Quench Protection (TSQP) The Heat Transfer Measurements Task. Development and operation of a test facility to measure heat transfer to helium through Nb 3 Sn conductor insulation to investigate temperature margins of superconducting magnet coils under heavy beam losses completed with the publication of the final report in December 2007 (CARE-Report-2007-033-NED) (CEA and WUT; task leader: B. Baudouy, CEA)

9. CARE08, Dec 4 2008, G. de Rijk, Summary report on NED activities 9 Work Package 2: TSQP – Heat Transfer Measurements Task (1/7) The first part of the Heat Transfer Measurements Task was to design and build a new He-II, double-bath cryostat. The cryostat was built by Kriosystem in Poland under the supervision of Wroclaw University according to specifications written by CEA. The cryostat was delivered to CEA on 20 Sept. 2005 and was commissioned in Sept. 2006. Views of NED cryostat (Courtesy M. Chorowski, WUT)

10. CARE08, Dec 4 2008, G. de Rijk, Summary report on NED activities 10 Work Package 2: TSQP - Heat Transfer Measurements Task (2/7) Characterization of the thermal performance of the magnet insulation  Classical insulation and Innovative insulation  “real situation” (coil) and on the insulation itself The drum experiment  Determination of the thermal conductivity and Kapitza resistance The stack experiment  Test on a stack of conductors closed to the coil mechanical, geometrical and heat transfer configurations Collaboration CEA-Saclay, KEK, CERN and RAL  Tests in He II at CERN and Saclay, Tests in SHe at KEK  Construction of a Double bath Cryostat (WUT and CEA- Saclay)  Construction of molds by KEK  Collaboration with CERN

11. CARE08, Dec 4 2008, G. de Rijk, Summary report on NED activities 11 Work Package 2: TSQP - Heat Transfer Measurements Task (3/7) RAL insulation – Construction of the 1D support for thermal resistance in HeII Tests Heat transfer measurement perpendicular to the insulation (1 D) ◦ Determination of the thermal conductivity ◦ Determination of the Kapitza resistance

12. CARE08, Dec 4 2008, G. de Rijk, Summary report on NED activities 12 Work Package 2: TSQP - Heat Transfer Measurements Task (4/7) RAL insulation –Example of Measuring Results, l=0.073 mm Evolution of the temperature difference across the sample with heat flux as a function of the bath temperature. –Kapitza Resistance and Thermal Conductivity

13. CARE08, Dec 4 2008, G. de Rijk, Summary report on NED activities Work Package 2: TSQP - Heat Transfer Measurements Task (5/7) Test with a “Saclay stack” ▫ Central conductor heated ▫ Insulation all polyimide (Kapton) ◦ 1 st layer : Kapton 200 HN 50 μm x 11 mm 2 wrappings (no overlap) ◦ 2 nd layer Kapton 270 LCI 71 μ m x 11 mm 2 mm gap ▫ 60 MPa 13 LHC beam Losses

14. CARE08, Dec 4 2008, G. de Rijk, Summary report on NED activities Work Package 2: TSQP - Heat Transfer Measurements Task (6/7) Courtesy of F. Rondeaux (CEA) Tests on innovative ‘ceramic’ insulation ▫ One wrapping with 50% overlap ▫ Heat treatment of 100 h at 660 °C ▫ 10 MPa compression only ! ▫ 5 conductors heated 14

15. CARE08, Dec 4 2008, G. de Rijk, Summary report on NED activities 15 Work Package 2: TSQP - Heat Transfer Measurements Task (7/7) Very small ΔT, at least one order of magnitude smaller than for the LHC insulation tests LHC beam Losses LHC upgrade beam Losses

16. CARE08, Dec 4 2008, G. de Rijk, Summary report on NED activities 16 Work Package 2: TSQP – Quench Computation task To study the protection of NED-like, high-field Nb 3 Sn accelerator magnets (INFN-MI; task leader: G. Volpini). Task was completed in early 2006 and a final report has been issued. Computations have been carried out for 1-m, 5-m, and 10-m long, 88- mm-aperture cosθ, layer designand 5-m-long, 160-mm-aperture, cosθ, slot design. Simulation results for 10-m-long model (Courtesy M. Sorbi, INFN-Mi) Both designs can be protected, using active quench protection heaters. Heaters

17. CARE08, Dec 4 2008, G. de Rijk, Summary report on NED activities 17 Work Package 3: Conductor Development (CD) The CD Work Package includes two main Tasks –conductor development Aim of the contract with SMI/EAS is to produce Powder-In-Tube type Nb 3 Sn conductor. (1.25 mm diameter strand, J c =1500 A/mm 2 @ 15 T in 0.05 mm filaments or 3000 A/mm 2 @ 12 T ) Two industrial contracts under CERN supervision: Alstom/MSA (F) and EAS/SMI (NL/D); Task Leader: L. Oberli –conductor characterization (CEA, INFN-Ge, INFN-Mi, and TEU; Task Leader: A. den Ouden, TEU) It is the core of the Program and absorbs ~70% of the EU funding. It is complemented by two extensions of scope –FE wire model development to simulate cabling effects (INFN-Ge & CERN; Task Leader: S. Farinon, INFN-Ge), –heat treatment study (CERN; Task Leader: C. Scheuerlein).

18. CARE08, Dec 4 2008, G. de Rijk, Summary report on NED activities 18 Work Package 3: (CD): Status of the SMI contract (1) Following successful R&D (step 2) including the cabling trial of a 40- strand Rutherford cable (LBNL), EAS/SMI launched the final strand production in fall 2007. A first 1000 m long strand, B228, produced partly at Hanau (EAS) and partly at Enschede (SMI) delivered to CERN in April 2008. A second strand, B230 (1650 m), was completely produced at Hanau. This strand was delivered to CERN in July 2008. Since July 2008, equipment transfer from SMI to EAS was completed.

19. CARE08, Dec 4 2008, G. de Rijk, Summary report on NED activities 19 Work Package 3: (CD): Status of the SMI contract (2) An additional strand of 3.8 km is currently under fabrication at Hanau (final steps). It was delivered in November 2008. The remaining 6.3 km of PIT strand are currently in production. They are expected to be delivered to CERN into two strand batches in December of 2008 (or possibly in January 2009). The strands B228 and B230 (partly) were used to produce at CERN a 14-strand cable (9.7 mm width and 2.2 mm thickness) for Short Model Coil (SMC) program. A 138 m long SMC cable was successfully produced in early September 2008. 19

20. CARE08, Dec 4 2008, G. de Rijk, Summary report on NED activities 20 Work Package 3: (CD): Status of the Alstom contract (1) With cold work method (1 st Way), Alstom produced a strand which included 78 sub-elements (~ 85 µm in diameter). This fabrication was characterized by workability problems (numerous breakages). This strand (binary Nb 3 Sn) showed a non-copper J c ~ 2000 A/mm 2 at 12 T and 4.2 K. The second way (extrusion) used to guarantee fair cohesion between Nb barrier and Cu can, especially important when increasing the number of sub-elements (to decrease filament size down to 50 µm, as requested by specification). Then, B1/63468 strand (2 nd Way) was produced into a single length of 1300 m, showing a very fair workability. This strand includes 246 sub-elements (~ 54 µm in diameter). In order to further check the strand workability, the B1/63468 was successfully drawn down to 0.8 mm diameter, corresponding to 35 µm in diameter sub-elements!!

21. CARE08, Dec 4 2008, G. de Rijk, Summary report on NED activities 21 Work Package 3: (CD): Status of the Alstom contract (2) However, disappointing critical current density for B1/63468: J c ~1500 A/mm 2 at 12 T and 4.2 K. Many efforts done at CERN to try to optimize heat treatment but without significant success (1600 A/mm 2 maximal value reached). The main reason for this low J c seems to be the big Nb 3 Sn grains observed by means of SEM (poor pinning). Therefore using Ta additions, leading to ternary Nb 3 Sn, should limit grain growth and then enhance J c (up to 40-50 %). Therefore, two billets currently fabricated by Alstom by cold drawing process (way 1) with Nb-Ta filaments to get ternary Nb 3 Sn phase. Around 1.5 km long and 6 km long strands respectively expected by December 2008. Extrusion process continued in parallel (Ta-alloyed Nb 3 Sn) (Way 2). Raw material (especially Nb tubes) already ordered from supplier. 15- 20 km of strand expected by March 2009. 21

22. CARE08, Dec 4 2008, G. de Rijk, Summary report on NED activities 22 Work Package 3: (CD): Planning of final strand delivery Firm Total [km] Delivered [km] 10/08 11/08 12/08 03/09 EAS/SMI12.72.6-3.86.3- Alstom24--1.5615-20 22

23. CARE08, Dec 4 2008, G. de Rijk, Summary report on NED activities Work Package 3: (CD): Conductor characterization (1) EAS/SMI B215 wire B215 is the successful prototype wire developed by SMI during Step 2. According to its design, the final strand is currently produced. This strand has 288 filaments (~ 50 µm), 84 h @ 675 o C: J c ~ 2500 A/mm 2. Heat treatment optimization studies at CERN: general trend was to decrease reaction temperature but increase duration to try to decrease Nb 3 Sn grain size. 320 h @ 625 o C: - 12 T and 4.2 K: I c > 1500 A, J c > 2700 A/mm 2, + 10 %!! - 15 T and 4.2 K: I c > 818 A (NED spec.), J c ~ 1500 A/mm 2 - RRR ~ 220 (vs 80 for 84 h @ 675 o C): much better for stability Reasonable cabling degradation of 5-6 % (as compared to 10-13 % for 84 h @ 675 o C). 23

24. CARE08, Dec 4 2008, G. de Rijk, Summary report on NED activities 24 Work Package 3: (CD): Conductor characterization (2) EAS/SMI B215 wire (continuation) Stringent NED specification fulfilled!! B c2 K = 26.3 T Courtesy of C. Senatore and R. Flukiger (Geneva Univ.)

25. CARE08, Dec 4 2008, G. de Rijk, Summary report on NED activities Work Package 3: (CD): Conductor characterization (3) EAS/SMI B215 wire SEM: Polished and fractured samples examined for standard and modified HT. 675 o C/84 h625 o C/320 h Un-reacted barrier ratio 23 % of total filament25 % of total filament Sn content24.2 at. % Sn24.7 at. % Sn Coarse grain ratio~ 30 % of A15 phase Mean fine grain size~ 180 nm~ 160 nm Sample with optimized HT: less reacted Nb 3 Sn but with higher quality: higher Sn content, B c2 K, T c and smaller grain size (160 nm vs 180 nm) coarse grain (~ 1-2 µm) fine grain (~ 200 nm) 25

26. CARE08, Dec 4 2008, G. de Rijk, Summary report on NED activities Work Package 3: (CD): Conductor characterization (4) EAS/SMI: characterization of final strands B228 strand: Strand diameter: 1.255 mm, Cu/non-Cu = 1.18 When reacted 120 h @ 650 o C, J c ~ 2450-2510 A/mm 2, RRR > 140 Very similar to B215 strand: EAS/SMI able to reproduce nice perf. !! B230 strand: Strand diameter: 1.254 mm, Cu/non-Cu = 1.25 For sake of saving strand length for SMC cable, I c and RRR shortly measured at CERN together with wires extracted from SMC cable. However, according to EAS measurements: J c = 2513 A/mm 2 at 4.2 K and 12 T (650 o C/120 h). If confirmed, indication of smooth technology transfer from SMI to EAS. 26

27. CARE08, Dec 4 2008, G. de Rijk, Summary report on NED activities Work Package 3: (CD): FE wire model INFN-Genova has developed an (ANSYS®-based) mechanical model to compute (and, thereby, predict) the sensitivity of un-reacted, NED- type wires to transverse loading. This provides a unique tool to compare and optimize billet layouts with respect to cabling degradation. Side-by-side comparisons of computed and observed deformations of un-reacted “internal tin” (left) and “PIT” (right) wires (Courtesy S. Farinon, INFN-Ge) 27

28. CARE08, Dec 4 2008, G. de Rijk, Summary report on NED activities Work Package 4: Insulation Development and Instrumentation (IDI) The Insulation Development and Implementation Work Package includes two main Tasks –studies on “conventional” insulation systems relying on ceramic or glass fiber tape and vacuum-impregnation by epoxy resin (CCLRC/RAL; Task Leader: S. Canfer) Completed with a final report in March 2007 –studies on “innovative” insulation systems relying on pre- impregnated fiber tapes and eliminating the need for a vacuum impregnation (CEA; Task Leader: F. Rondeaux). Completed with a final report in December 2007 (CARE-Report-2007-037-NED) 28

29. CARE08, Dec 4 2008, G. de Rijk, Summary report on NED activities 29 Work Package 4: IDI CCLRC/RAL has evaluated a polyimide- sized glass fiber tape that is able to sustain the required Nb 3 Sn heat treatment without degradation and which seems a promising solution to conventional insulation. This is being used for the Short Model Coils. The Innovative Insulation Task is built upon an ongoing R&D program at CEA which has demonstrated the feasibility of such a system (2 patents); the efforts are now concentrated on characterizing and improving the mechanical properties of the insulation. A Short Model Coil is being prepared with this technology. Polyimide-sized S2 glass fiber tape (Courtesy S. Canfer, CCLRC/RAL) Heat-treated conductor stack with CEA innovative insulation (Courtesy F. Rondeaux & P. Fourcade, CEA)

30. CARE08, Dec 4 2008, G. de Rijk, Summary report on NED activities Working Group: Magnet Design and Optimization (MDO) The Magnet Design and Optimization (MDO) Working Group is made up of representatives from CCLRC, CEA, CERN and CIEMAT (Chairman: F. Toral, CIEMAT). The Working Group has completed its comparison of selected 2D magnetic configurations. In parallel, CERN has completed its optimization of 2D 88-mm- aperture, cos , layer magnetic design (Reference Design V2) STFC/RAL has undertaken a 2D mechanical design. 30

31. CARE08, Dec 4 2008, G. de Rijk, Summary report on NED activities Working Group: MDO: dipole concepts Concepts studied for future High Field Dipoles Common coil (CIEMAT) Ellipse-type (CEA/Saclay) Double helix (RAL) Cos-  layer (CERN & RAL) Toroidal motor- Type (CIEMAT) Cos-  motor type (CIEMAT) Slotted cos-  (CIEMAT) 31 F. Toral ASC06, Seattle

32. CARE08, Dec 4 2008, G. de Rijk, Summary report on NED activities Working Group: MDO: 88 mm aperture comparison 32 F. Toral ASC06, Seattle

33. CARE08, Dec 4 2008, G. de Rijk, Summary report on NED activities Working Group: MDO: 88 mm aperture comparison Some common starting parameters and the figures of merit for a fair comparison have been stated. This paper summarizes the 2-D magnetic field calculations. For 88 mm aperture, the cos-  layer design is the best. However, for large apertures, the coil mid-plane stresses become too high. The most promising configuration for large apertures is the slotted cos-  dipole, as the rest of magnets have problems with the superconductor efficiency or with the fabrication complexity. – Remark: The mechanical realization (pre-stressing of the coil) of a slotted cos  is not (yet) known ! 33

34. CARE08, Dec 4 2008, G. de Rijk, Summary report on NED activities Working Group: MDO: cos  e-m design study 34

35. CARE08, Dec 4 2008, G. de Rijk, Summary report on NED activities Working Group: MDO: cos  mechanical design study 35 made a

36. CARE08, Dec 4 2008, G. de Rijk, Summary report on NED activities Outline Main objectives of NED NED structure and participants Achievements of the NED Work Packages NED continuity : Short Model Coil NED successor EuCARD - High Field Magnets 36

37. CARE08, Dec 4 2008, G. de Rijk, Summary report on NED activities 37 NED continuity : Short Model Coil (SMC) Participant funding only (formally outside FP6-CARE-NED ) STFC/RAL, CEA, CERN and LBNL to manufacture and test a series of LBNL-type Short Model Coils wound from NED-sub-cables cable and insulation performances in real coil environment design limits for transverse and longitudinal loads. 3 sets of coils to be tested in one structure Achieved in 2008: –All elements of structure were delivered by CEA to CERN, –3 coils ( 2 Cu + 1 Nb 3 Sn) wound @ CERN by RAL+CERN –Traces for instrumentation ordered at CERN –Connections mockup done at CERN NEXT steps: –Heat treatment of Nb 3 Sn coil in RALDec. 2008 - Jan 2009 –Instrumentation of the coil in RAL by CERNJan 2009 –Potting in RALFeb 2009 –Instrumentation of the structure by CERNDec. 2008 - Jan 2009 –Assembly test with dummy coilJan 2009 –Cold test of structure with dummy coilFeb 2009 Courtesy M. Bajko (CERN)

38. CARE08, Dec 4 2008, G. de Rijk, Summary report on NED activities SMC: a joint effort Magnetic design: CERN + RAL Mechanical design: CEA + CERN Components of the Structure : CEA Insulation : CERN + CEA Winding: CERN + CEA Heat Treatment + Potting: RAL Instrumentation: CERN @ RAL Assembly : CERN Test: CERN winding with trial low performance Alstom Nb 3 Sn cable 27-28. Nov. 2008 at CERN 38 Courtesy M. Bajko (CERN)

39. CARE08, Dec 4 2008, G. de Rijk, Summary report on NED activities Outline Main objectives of NED NED structure and participants Achievements of the NED Work Packages NED continuity : Short Model Coil NED successor EuCARD - High Field Magnets 39

40. CARE08, Dec 4 2008, G. de Rijk, Summary report on NED activities NED successor in EuCARD - High Field Magnets We now have the technology to build the magnet which was initially proposed for NED ! See more on Friday at the EuCARD kick-off meeting Task 2. Support studies –Certify radiation resistance of radiation resistant coil insulation and impregnation –Make a heat deposition and heat removal model for the dipole Nb 3 Sn model with experimental validation and determine the thermal coil design parameters for the dipole model magnet. Task 3. High field model –Design, build and test a 1.5 m long, 100 mm aperture dipole model with a design field of 13 T using Nb 3 Sn high current Rutherford cables. Task 4. Very high field dipole insert –Design, build and test HTS solenoid insert coils for a solenoid background magnet aiming at a field increase up to 6 T to progress on the knowledge of HTS coils, their winding and behaviour. This as in intermediate step towards a dipole insert. –Design, build and test an HTS dipole insert coil for a dipole background magnet aiming at a field increase of about 6 T. Task 5. High Tc superconducting link –Design of HTS bus: choice of HTS material definition of thermal conditions, requirements for stabilization and quench protection, modelling of quench propagation. –Design. realization and test of electrical joints and electrical terminations. –Mechanical design and assembly of a 20 m long superconducting link (26 pairs of 600 A). Task 6. Short period helical superconducting undulator –Design, build and test a prototype helical coil undulator magnet with 11.5 mm period, high peak magnetic field in Nb 3 Sn technology. 40