WORK IN PROGRESS F C C Main Quadrupoles FCC week 2017 Clement Lorin,Maria Durante,Helene Felice,Damien Simon - CEA Tiina Salmi – TUT Daniel Schoerling - CERN Berlin, 28 may 2017

EuroCirCol baseline WP2 G (T/m) Bpeak (T) Bore (mm) Length (units x m) MQ FCC 379.2* 12 50 750 x 6.0* MQ LHC 223 6.5 56 392 x 3.2 Number of apertures (-) 2 Inter-aperture spacing (mm) 250 194 Operating temperature (K) 1.9 Margin along the loadline (%) 14 19.7 Yoke OD max 800 452 *: Antoine Chance, WP2 leader, EuroCirCol

SC density / cable features Specifications of EuroCirCol project (16 T Nb3Sn dipole) Use of the cable of the cosine-theta* magnets Use of the demonstrator strand Φ = 0.7 mm ; cnc = 2.0 Strand (mm) 1.1 0.7 Nb of strands (-) 22 36 Bare cable width 13.2 13.3 bare mid-thickness 1.95 1.26 keystone angle (°) 0.5 Copper/nonCopper 0.8 2.1 *: V. Marinozzi & M. Sorbi (and all INFN ECC team)

*Todesco et al, Semi-analyticl approaches to magnet design, Wamsdo 2013 Rossi L., Todesco E. Electromagnetic design of superconducting quadrupoles, PRSTAB, 2006 30°

Dipole Low Field str&cable 401 T/m 473 tons (integrated grd) 86% LL 300 K Thotspot 2 possibilities -Cond qty reduction same gradient 420 tons & 399 T/m -Gradient increase same 2D cond qty 412 T/m & 460 tons 30°

4 layers designs 6 layers designs

Dipole High Field str&cable 367 T/m 530 tons 75% LL 350 K Thotspot 2 possibilities -Cond qty reduction same gradient -Gradient increase same 2D cond qty 412 T/m & 472 tons

Design emag Quantity v20ar Unit strand diameter 0.7 mm nb of strands 36 N/A width 13.3 average thickness 1.204 – 1.32 Cu/nonCu 2.1 Inom 12285 A Bpeak 12.12 T LL margin (1.9 K) 14.0 % Inductance diff. (2 ap) 17.9 mH/m Stored energy (2 ap) 1397 kJ/m Nb of turns 56 = 9+12+16+19 - F_/_ & F // (per ½-coil) 3.526* & 1.579 MN/m Hotspot 300 K Midplane shim 0.3 I/Ic max 0.61 Conductor area (2 ap) 124.2 cm² 750 x 6.0 x 8.7 weight 500 (dip ~7000 ) tons *0.55+0.8+1.1+1.1 MN/m per layer

Design emag Field quality beam injection nominal beam injection

Meca design Single aperture model, so far 32 mm thick shell 500 µm ← [Clement Lorin – Helene Felice - Damien Simon] Single aperture model, so far 32 mm thick shell 500 µm ← Ryoke = 275 mm Contacts/symmetry: sliding; 0.2 friction glued: coils with pole and the first 2 layers/ the last 2 layers

Coil stress v4 Contact at 105% σ von Mises σtheta 68 MPa -78 MPa After key insertion 420 T/m central gradient 105 % nominal 174 MPa -182 MPa -8 MPa +72 MPa 4.2/1.8 K 156 MPa -156 MPa 420 T/m

Meca design After key insertion 4.2/1.8 K 420 T/m Pole - Titanium 246 MPa 462 MPa 305 MPa 127 MPa 243 MPa 245 MPa Shell - Aluminum

Meca design Iron – Pad After key insertion 4.2/1.8 K 420 T/m Sigma von Mises 300 MPa 667 MPa 672 MPa Sigma I - tension 264 MPa 267 MPa

Meca design Iron – Pad After key insertion 4.2/1.8 K 420 T/m Sigma von Mises 223 MPa 428 MPa 460 MPa Sigma I - tension 77 MPa 73 MPa

Protection design [Damien Simon -CEA] Temperature: Everything quenched after 40 ms (validation+ heater delay): worst case - > 313 K (Tiina’s spreadsheet: 300 K) Voltage: less than 1.2 kV (600 V max) vgnd_max [V] time [s] vgnd per blocks

Conclusion Encouraging preliminary results:Emag-Mecha-Protection:ok with 250 mm interbeam quad at 400 T/m (Emag 2-in-1 and mechanics 1-in-1) Emag, room for improvement: high cnc -> keystone = 0.8° (only two wedges left?) cnc is reduced: 2.1 -> 1.8 (optimized design- no grading) Mechanics, still margin for optimization: get closer to reality (holes for assembly) adding bladder steps go to a 2-in-1 config!