Task7: NUSTAR2 - Design and Prototype Construction of a Radiation-Resistant Magnet

1. Task7: NUSTAR2 - Design and Prototype Construction of a Radiation-Resistant Magnet C. Mühle GSI Task leader: G. Moritz /GSI

2. High-radiation area Design parameters and layout of the Super-FRS

3. Recap of first year • Original idea: • Use of superconducting radiation resistant dipoles • Investigation of radiation loads: • Heat load on the cryogenic system for a 5 ton magnet: ≈ 2.3 kW (expected FAIR cryogenic power: 20 kW) => economic operation not possible • Decision • Normal conducting magnets with mineral insulated cable (MIC) • Surveying and alignment system for high-radiation areas • Not directly influenced by this decision • => Main work in 2006 was dedicated to the conceptual design of a dipole with MIC

4. Conceptual design of a dipole with MIC: Cooling • Cooling options: • direct: hollow conductor • indirect: solid conductor + radiator • Direct cooling: • Advantage: good heat transfer • Disadvantage: radiolysis • Indirect cooling: • Advantages: • pressure drop and cooling power can be designed independently from coil • no radiolysis • water and power connectors separated • Disadvantage: limited heat transfer • Decision: indirect cooling

5. Conceptual design of a dipole with MIC: Coil • Conductor: • Cable Size 19mm x 19mm • Sheath Thickness 1 mm • Insulation Thickness 1 - 1.5 mm • Cond. Area 190 mm2 • Unit Length 100m • Radiator: • Copper plate 12 mm thick • Stainless steel tube 10x1mm • Coil system: • 2 x 192 turns, 12 columns, 2 x 16 layers • 2 x 8 double pancakes • ≈ 100 m conductor per single pancake • total conductor length ≈ 3.2 km

6. Conceptual design of a dipole with MIC: Yoke • Requirements: • α=11°, r=12.5m, Bmax=0.15-1.6T L=2.39m • Useful aperture 380x140mm (ΔB/B≤±2x10-4) • Gap height 170mm • Yoke design • H-type • Curved • Laminated • thickness 2 bis 4 cm • cut by laser • final milling of pole profile • Cross section 2740mm x 2020 mm • Yoke weight 85 t • Pole shims but no active correction • Longitudinal split into 3 parts

7. Conceptual design of a dipole with MIC: Dipole operation • I=610A • P=122kW • Cooling • ΔT=21.9K • 79.2 l/min @ 1bar • Conductor temperature: • Return water temperature +40K

8. Construction of a prototype dipole with MIC • To be done in the remaining project time: • Manufacturing design • Production of tooling and first (test) double pancake • Production of full coil • Production of yoke • Assembly of final magnet • Time scale • ≈ 1 year => close to the limit, but still feasible • Cost estimation of prototype magnet incl. tooling: 1.5 M€ • Budget • This task: 568 k€ (50%EU,50%GSI) • Budget gap: ≈ 950 k€ • Redirect money from other tasks • Finance remaining gap by GSI

9. Surveyingand alignment system for high-radiation areas • Measurement concept and simulation of alignment approach nearly finished • Photogrammetric solution on Super-FRS target area working platform with four cameras on two movable vehicles • Sequential photogrammetric survey of inaccessible areas during shutdown

10. Surveying and alignment system for high-radiation areas Problems to solve: • mounting and fiducialization of excentric magnet points • Penetration of shielding between magnets and working platform • Remote-controlled adjustment of magnet positions (radiation! weight!)