1 超伝導電磁石／鉄ヨーク／実験室について 高エネルギー加速器研究機構 山岡 広 田中 賢一 目 次 ・概 要 ・ 超伝導電磁石について ・ 鉄ヨークについて ・ 実験室について ・まとめ Jun. 28, ‘06

2 Introduction Yoke Design - Design against magnetic field - Design against forces - Assembly procedure - Cable path - Support for sub-detectors - Access plan to the sub-detector Solenoid Design - Coil/superconductor design - Cryostat design - Coil support - Assembly/Installation - Thermal design - Cryogenics system Cable Earthquake Self-weight Mag. force Solenoid magnet Iron Yoke B Uniformity H-Cal EM Cal TPC Muon Tracker VTX Solenoid/Iron yoke Magnetic field: 3T Mean radius: 4m Uniformity(TPC): <2mm Leakage <50gauss 17m 16m

3 2 layers coil + Correction Coil(4 layers) 4.2mm 30mm 4.3mm NbTi:Cu:Al= 1:0.9:15.6 Strand diameter: 1.23mm Filament diameter: 20  m Jc in NbTi at 5T, 4.2K: > 2750A/mm 2 Ic at 5T, 4.2K: > 20300A (Based on ATLAS coil) Superconductor 6.5mm 45mm 2 layers 4 layers 50cm t30mm Solenoid magnet について t40mm t60mm t100mm Al support cylinder

4 Von Mises Axial direction Compression Stress level in the coil (By K. Tanaka) Development of High-strength Al 4.43m(Half) R4.0m Support cylinder (t=30mm, Aluminum) Conductor (h=45mm) 7mm 3mm Deformation of the coil (By K.Tanaka) Solenoid center By Makida Circum. direction

5 Design of Coil supports (by K. Tanaka) Static loads - Cold mass: 78 tons - De-centering force: 380 tons (Axial) (Unbalance force) 130 tons (Radi) ZZ RR Coil Iron De-centering force (Unbalance force) Coil supports - Thermal load: 5 Watt - Thermal shrinkage: 40mm(Axial) 20x10e-6/ ℃ 20mm(Phi) Rough estimation;  60mm, 6x2 rods(Phi), 14 rods(Axial) Axial dir. Phi dir. Detail design is necessary.

6 118MPa<140MPa 9mm t=40mm (Outer vac. wall) t=60mm (Inner vac. wall) t=100mm (End plate) 2000tons Fixed 2000tons x 0.3G Fixed 9mm 125MPa Cryostat Material: Stainless steel Outer vac. Wall: 40mm Inner vac. Wall: 60mm End plates: 100mm Assumption Weight of calorimater is supported on the inner vacuum wall.

7 Assembly procedure Coil assembly process Winding Machine Reference: SDC Thin superconducting solenoid view graphs for the DOE review presentation Oct , ‘92

8 Magnet assembly process Reference: SDC Thin superconducting solenoid view graphs for the DOE review presentation Oct , ‘92 Outer vac. vessel

9 鉄ヨーク 鉄ヨークの設計について ・磁場に対する設計 磁場均一度、漏れ磁場 → 鉄形状最適化 ・力に対する設計 自重、地震力、電磁力 < 許容 値 → 支持形状の検討 ・組み立て方法等 容易な据え付け及び精度の確 保 ケーブル及び測定器のサポー ト メンテナンス ・コストの抑制 自 重 電磁力 3 T 超伝導電磁石 地震 磁場 ケーブル

10 Coil-L Coil-MCoil-C io 4.25m R4.0m dz Added! J corr /J main 磁場に対する設計

Distance from center (m) Uniformity (mm) R=0.4m R=0.6m R=0.8m R=1.0m R=1.2m R=1.4m R=1.6m R=1.8m R=2.0m R=2.05m 10m Magnetic field (t=50cm:4 th,5 th ) Air Gap 50cm 25cm Magnetic field along the beam axis. 漏れ磁場 磁場均一度 < 2mm

12 Support positions Thickness= 5cm Stress level is small enough. 0.3G 1.4mm 8250tons 2.8mm Self-weight Seismic force 構造解析

13 Support plate: 75mm-thick 170MPa 2mm Support plate 18400tons

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15 Assembling procedures Dodecagon(12 gon) Barrel Yoke Transportation limit 3.2W x 12m Length Iron plates to be bolted on the support frame Support jig at each corners

16 End Yoke Iron plates (blue parts) are assembled by welding. Upper/Lower end yoke is ssembled by welding. Put them on the support stand

17 Solenoid installation Solenoid During maintenance Experimental hall ・エレキ小屋？ ・チムニー？ ・冷凍機関係？

18 Solenoid magnet Coil: 78tons Outer Vac. Wall(SUS, t40mm): 81tons Inner Vac. Wall(SUS, t60mm): 105tons Bulk heads: 25tons Other components: 4tons Total weight: 215tons End-Yoke(One quadrant) 1000tons

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20 12m Steady state Open the end yoke Moving Maintenance position Way to open the end yokes

21 - Detail design of the coil supports will be done. - Solenoid support configuration will be made. - Assembly/Installation plan should be considered. Solenoid Magnet 2 layers 4 layers 50cm - Leakage field must be acceptable. - Difference between octagon and dodecagon is not so large. - Support configuration for the magnetic force should be considered. - Realistic end-yoke moving device should be designed. Conclusion t30mm Al support cylinder

22 - General design - Magnetic field: 3T - Size: 4m radiusx8.86m length - 2 layer (Main coil) + 4 layer (Correction coil) - Calorimeter: Inside of the solenoid - In-direct cooling - Coil design Superconductor: 6.5mm x 45mm Magnetic force on the coil: 130MPa max. Coil support design - Cold mass(78 tons) + Decentering force(380 tons) - Thermal shrinkage/Load (60mm dia., 6x2 rods in phi, 14 rods in Z.) - Cryostat design - O.rad: 4.4m x I.rad: 3.72m x Length: 9.5m - 40mm(Outer), 60mm(Inner), 100mm(End) Support configuration for Calorimeter - Make engineering drawings. - Assembling procedure - Thermal design - Cryogenic design 6.5mm 45mm 今後の課題 (Solenoid magnet)

23 - Magnetic field design Optimization of yoke configuration in several conf. Boundary conditions - <2mm in TPC volume, <50 gauss at 10m from I.P. - Detector region: R3.5m, Z= 4.25m - Mechanical design Stress/deformation against; - Magnetic force: tons - Self-weight: 8250 tons(B.Y) - Seismic force: 0.3G in the horizontal direction Precise calculations are necessary. Detail design of support structure - Make engineering drawings of; Iron yoke, Barrel yoke, End yoke - Assembling procedure Barrel yoke, End yoke - Experimental hall (Not fixed!) - Layout - E.Y. moving mechanism Detail design is necessary. 今後の課題 (Iron Yoke) おわり

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25 磁場に対する設計 - 磁場均一度： < 2mm - from I.P. < 50gauss ⇒ 鉄形状の最適化 ・超伝導電磁石 - 中心磁場： 3T - 半径： 4m - 全長：～ 9m 鉄の飽和と均一度の改善 要求 超伝導電磁石 Z2 R2 R1 Z1 Z1 、 R1 を最小化 Z2 、 R2 を最適化 均一度： <2mm

26 Dodecagon Octagon

27 (a) 500mm-thick iron (b) 250mm-thick iron (c) mm-thick iron Leakage field: <50 gauss at 10m from I.P.