EuCARD2 Magnet Status and action plan 19/09/2014 Maria DURANTE Thanks to EuCARD2 Task 10.3 members

Magnet concepts under study Starting from cable propositions from Task 10.2 : Block / stacked tapes cable Aligned Block design Cosine-theta design CCT design

Block with YBCO stacked tapes cable John Himbele JE = 400 A/mm² Low cost cable Woundable cable : “twist and bend” to avoid hardway bending BUT Non-continuous transposition of the stacked tapes  cable transposition at coil ends or between coil layers Mechanical strength, twisted regions

Block with YBCO stacked tapes cable - status 2D Electromagnetic design done 3D electromagnetic design on going Twist region configuration studies on going FE Magnet mechanical model to be done Winding test set up under study tapes block transposition twist region mechanical support

Aligned block with YBCO Roebel cable Jeroen Van Nugteren The two plots present flux path variation for insert magnet: (left) standalone in Iron , (right) in 13T ideal background field Magnetic Field [T] Note! Yellow area is the high short sample position. Very different from std. LTS magnets. Percentage on Loadline [%]

Aligned block with YBCO Roebel cable - status 2D and 3D Electromagnetic design done End optimization done Mechanical model of the Roebel cable done Tests on Roebel cable insulation and mechanical reinforcement on going FE Magnet mechanical model to be done Sub scale model FeaTher-M0 Aim: Quench detection & coil production Electromagnetic Design completed Components almost ready  End of September At least 3 short scale models are foreseen : First SS one by the end of the year SC Roebel cable needed for the others HTS insert magnet proposal (EuCARD2 baseline?) : Feather-M2 CAD design ongoing

Cosine-Theta with YBCO or BSCCO cable Clément Lorin Iron yoke 5 T YBCO Roebel cable 3.7 T BSCCO Rutherford cable 3.7 T HTS dipole inside FRESCA2 magnet - Lorentz forces

Cosine-Theta with YBCO Roebel cable - status First cos-theta design proposal: 2 layers, 10-mm wide Roebel cable 2D Electromagnetic design done End optimization ongoing FE Mechanical model done Field [T] ET thickness [mm] Prestress Peak stress [MPa] 5.00 5.5 Yes 146 No 118 8.0 187 100 16.78 782 684 805 600 20.0 30 250 Show stopper: Mechanical structure for double layer cosine-theta too weak.

Cosine-Theta with YBCO Roebel cable - status First cos-theta design proposal: 2 layers, 10-mm wide Roebel cable 2D Electromagnetic design done End optimization ongoing FE Mechanical model done  show stopper New design proposals under study Cos-theta 1 layer / thicker structure design 12 mm Roebel cable Mechanical design done Short model coil to be designed CAD detailed design foreseen from Nov 2014 12 mm 15.5 mm Field [T] ET thickness [mm] Prestress Peak stress [MPa] 5.00 15.5 Yes 220 No 35 17.16 570 150 Seems to be achievable.

Activities at CEA next year

Spares

Task 10.3 SCHEDULE

Task 10.3 DELIVERABLE AND MILESTONES EuCARD² Deliverable and milestones D10.1 Conceptual study of HTS accelerator magnets (report) M18 The report must contain all key elements of the novel magnet design, considering electromagnetics, mechanical, thermal, stability and protection aspects. MS64 YBCO magnet design report M18 MS68 Technical and economical comparison YBCO/Bi2212 magnets M36 Internal milestones proposal IMS01 Inputs for magnet HTS design M3 IMS02 HTS magnet(s) detailed design M24 IMS03 HTS magnet(s) built M40  D10.4 for task 10.4 : Magnet Cold test M44

Magnet specifications Parameter name Symbol Value YBCO Magnet Value Bi-2212 Magnet Remarks MAGNET Central field B0 5 T Up to 5 at 4.2 K (20% margin on loadline) Clear bore aperture Φb 40 mm 40 High energy LHC dipole magnet (beam size 25-28 mm) Operational temperature T 4.2 K 4.2 1.9 K also possible 77 K tests during magnet realization Current at 20 T I 5 to 10 kA 5 to 10   Stray magnetic field Bout ≤ 0.2 T At border of cryostat Magnetic multipoles at 2/3 Φb bn 5 10-4 - Geometric 30 10-4 Including magnetization and persistent current (best effort) Magnetization M 300 mT 300 Allowing fast ramping up Straight section length L ≥200 mm ≥200 As short as possible while remaining compatible with field quality for YBCO Magnet length LM < 1500 mm 700 mm uniform field (Fresca2) Grenoble test facility Magnet outer diameter ΦM < 99 mm () < 140 mm x 90 mm (rect) Without yoke – Outsert candidates : FRESCA2 (100 mm) or EDIPO (143 mm x 93 mm) CONDUCTOR Engineering critical current density (20T, 4.2K) JE, 20T 600 A/mm² In strand/tape at field perpendicular to wide face Available cable Engineering critical current density (20T, 4.2 K) 400 A/mm² For small development magnets Bare cable width wcbl 10-12 mm 10-15 Provisional Bare cable thickness at 50 MPa tcbl 0.8-1.2 mm 1.5-2.0