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MQXF coil cross-section status. Paolo Ferracin. HiLumi WP3 Video-meeting 28 August, 2012. Outline. Update of MQXF coil cross-section with cable growth during reaction (from v2 to v3) Length of coil ends. From HQ to MQXF: m agnetic design concept (presented on July 26). HQ. MQXF_v2.
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MQXF coil cross-section status Paolo Ferracin HiLumi WP3 Video-meeting 28 August, 2012
Outline Paolo Ferracin Update of MQXF coil cross-section with cable growth during reaction (from v2 to v3) Length of coil ends
From HQ to MQXF: magnetic design concept(presented on July 26) HQ MQXF_v2 Paolo Ferracin • Aperture: from 120 mm to 150 mm • Cable width: from 15 mm to 18 mm wide cable • 2 layers with similar angles and 4 blocks • All harmonics below 1 unit at 2/3 of Rinand 80% of Iss • Similar iron geometry, but with OD from 520 mm to 558 mm
Cable and coil parameters(presented on July 26) HQ MQXF_v2 Paolo Ferracin • From HQ to MQXF • Wider cable • Increased insulation • 43% more conductor
New cable dimensions HQ MQXF_v3 Paolo Ferracin • Cable growth during reaction (unconfined heat treatment ) taken into account • 2.0% in width • 4.5% in mid-thickness • Same keystone angle • Similar inner layer • Outer layer wedge slightly higher • One turn less in outer layer • Do we still want it? • Or FRESCA2-type of layer jump?
Cable and coil parameters HQ MQXF_v2 MQXF_v3 Paolo Ferracin
Conductor properties Paolo Ferracin • From 0.80 to 0.85 mm strand • Cu/Sc ratio: 1.13 (53% Cu) • Assumption on Jc • 2500 A/mm2 at 12 T • 1400 A/mm2 at 15 T • Resulting Jc for computations with self field correction • 2650A/mm2 at 12 T • 1450A/mm2 at 15 T • Values consistent with D. Dietderich and H. Felice presentation and with FRESCA2 PIT strand data
Magnet parameters at 1.9 K HQ MQXF_v3 MQXF_v2 Paolo Ferracin
Stress analysis • Lorentz stress on mid-plane • IL: -101 MPa • OL: -121 MPa • Bladder press. / interf. • 17MPa / 0.160 mm • Max shell stress: 150MPa • Lorentz stress on mid-plane • IL: -110 MPa • OL: -126 MPa • Bladder press. / interf. • 27MPa / 0.410 mm • Max shell stress: 229MPa HQ MQXF_v3 Paolo Ferracin
Stress analysisCoil peak stress HQ @ 1.9 K -137 MPa MQXF_v3 @ 1.9 K -149 MPa HQ @ Gnom -119 MPa MQXF_v3@ Gnom -128 MPa Paolo Ferracin
Outline Paolo Ferracin Update of MQXF coil cross-section with cable growth during reaction (from v2 to v3) Length of coil ends
Estimate of MQXF length of coil ends Paolo Ferracin • The HQ case • Magnetic half-length • 420 mm • Coil half-length: • 508 mm • End length (return end) • 90 mm • The MQXF • End length (return end) • 90*(150/120) = 113 mm -> 120 mm • Proposed “lengths of the region which includes everything between the portion of the magnet exceeding the magnetic length to the portion of the next magnet exceeding the magnetic length (R. De Maria)”, in the non-connection side • 500 mm
Estimate of MQXF length of coil ends Paolo Ferracin • The HQ case • End-shoe thickness • ~40 mm • End-shoe extension for NbTi-Nb3Sn splice • ~150 mm • MQXF (connection side) • Can we incorporate the end plate in the NbTi-Nb3Sn splice extension (solution adopted in HD2/HD3)?
Appendix Paolo Ferracin
From HQ to MQXFMechanical design concept HQ MQXF Paolo Ferracin • Same support structure concept as HQ • Same shell thickness, but OD from 570 mm to 608 mm • Cooling holes and busbar slots added • 10 mm thick LHe vessel included within 630 mm OD
Fringe field MQXF HQ Paolo Ferracin • At 5 mm from the cryostat, fringe field ranging from 3 mTfor HQ to 8 mTfor MQXF
Stress analysis • Lorentz stress on mid-plane • IL: -101 MPa • OL: -121 MPa • Bladder press. / interf. • 17MPa / 0.160 mm • Max shell stress: 150MPa • Lorentz stress on mid-plane • IL: -113 MPa • OL: -122 MPa • Bladder press. / interf. • 27MPa / 0.430 mm • Max shell stress: 230MPa HQ MQXF_v2 Paolo Ferracin
Stress analysisCoil peak stress HQ @ 1.9 K -137 MPa MQXF_v2 @ 1.9 K -150 MPa HQ @ Gnom -119 MPa MQXF_v2@ Gnom -129 MPa Paolo Ferracin
Some additional considerations on MQXF (II) Paolo Ferracin • Cooling holes • 80 mm diameter • Could be increased to 90 mm, depending on axial support system • Busbar • 20 x 50 mm slot • Axial support • 32 mm axial rods • Some space for end-plate and pad-bolts • High stress but probably still fine • Alternative: end-plate welded to vessel
Some additional considerations on MQXF (III) • LHevessel • 10 mm thick cylinder • OD: 630 mm • 1 mm gap between vessel and Al shell (nominal dimension) • About 0.500 mm clearance after pre-loading, cool-down, and excitation • Still to be verified the welding procedure • Other modifications/simplifications • Round collars? • No masters? MQXF Paolo Ferracin