1. Orbit Correctors in D2 and Q4 Update J. Rysti and E. Todesco 1 4/11/2014

2. Requirements Integrated field 4.5 Tm (dual 3 T & 1.5 m). Multipoles below 10 units at all operational fields and configurations. Apertures operated completely independently. Cross-talk problem. Evolution of design parameters: 2 4/11/2014 Aperture:105 mm100 mm105 mm Beam distance: 194 mm194 mm188 mm

3. Solutions 3 4/11/2014 H/V configuration. Use FeCo alloys, which have high saturation inductions. Lower the maximum operational field so that multipoles < 10 units (make longer magnets).

4. FeCo alloys 4 4/11/2014

5. FeCo alloys 5 4/11/2014 High saturation fields (~ 2.4 T). Best performance: 49% Fe, 49% Co, 2% V. Must be heat treated at around 900 ° C. Magnetic properties somewhat sensitive to stress. Low temperature data missing... Never used for superconducting magnets before. Heat-treated FeCo materials cost ~ 80 €/kg.

6. Collar thickness & FeCo vs. Fe 6 4/11/2014 16 mm collar thickness25 mm collar thickness

7. Multipoles 7 4/11/2014 Both apertures powered equally Ref. radius = 2/3 aperture

8. Multipoles 8 4/11/2014 Multipoles in aper. 2, when aper. 1 is powered

9. FeCo alloys 9 4/11/2014 Heat-treated FeCo materials cost ~ 80 €/kg. Entire yoke FeCo (using 100 €/kg) ~150 000 €. FeCo not needed everywhere => ~40 000 €. In the example on the right, multi- poles below 10 up to 2.7 T.

10. Laminated iron/steel collars? Make the ”floating collars” from iron. Iron closer to the coils, stacking factor 0.5. However, would cause saturation at lower fields -> worse field quality (self-saturation). 10 4/11/2014

11. Mechanical study 16 mm collars enough? 11 4/11/2014 Iron yoke in the magnetic simulation (3 kA, 2.6 T), no yoke in structural.

12. To be done More mechanical analysis. Thermal properties. 3D effects on field quality. Remarks: If max. operational fields lowered from 3 T to 2.8 T => +10 cm to magnet length 2.5 T => +30 cm to magnet length 2 T => +75 cm to magnet length 12 4/11/2014

14. Extra slides 4/11/2014 14