Analysis of TF Load Paths and Vacuum Vessel Loading

1. Analysis of TF Load Paths and Vacuum Vessel Loading H. M. Fan Jan. 22, 2009

2. Upper PF1B Outer TF coil Upper PF1C Upper PF1A Upper PF2 Upper PF3 Upper PF4 OH Upper PF5 Inner TF coil Lower PF5 Lower PF4 Lower PF3 Lower PF2 Lower PF1A Lower PF1C Lower PF1B TF and PF Coils

3. Al block assembly Flexible TF coil Tension only tie rod Ring bar Tension only tie rod Ring bar Flexible TF coil Al block assembly Outer TF Coil Supports • Outer TF leg is supported by umbrella structure, tie rod, ring bar and vacuum vessel • The ring bars and tie rods may reduce the in-plane and out-of-plane forces at the umbrella structure

4. Max. and Min. Upgraded PF Coil Currents

5. Fz = 11617 lbs Fz = 42664 lbs Fr = 13969 lbs F = 48793 lbs Fr = 42628 lbs 6285 lbs 32615 lbs 0 lbs 0 lbs 2130 lbs 50347 lbs 32615 lbs 6285 lbs 32615 lbs 2130 lbs 50347 lbs 0 lbs 0 lbs 32615 lbs Reactions of Outer TF Leg w/wo Upgrade Note: For the upgrade coil currents, forces in the ring becomes compression. F = 12177 lbs tension compression TF=130, OH=-24, PF1a=-4, PF1b=-8, PF1c=-10, PF2=0, PF3=-16, PF4=-20, PF5=-32, PL=0 6285 lbs TF=71.16, OH=-20, PF1a=-11.35, PF2=-16.93, PF3=-18.83, PF4=-10.73, PL=1000 No PF5 6285 lbs

6. Radial Displacement of Ring Bar Decides the Ring Force – For Currents without Upgrade At ring, the radial displacementis 0.114 mm

7. Radial Displacement of Ring Bar Decides the Ring Force – For Currents with Upgrade At ring, the radial displacement is -0.613 mm

8. Structural Responses to Ring and Tie Rod Variations Note – The results above are responses of upper Aluminum block, ring bar and tie rod. Force is mainly in vessel plane Negative force mean compression

9. Vertical Reactions of PF2 to PF5 Coils

10. Vacuum Vessel Model • 90° cyclically symmetric model • All ports with covers • Not include TF coils, but the TF loadings were applied on the umbrella structure and the vacuum vessel • Not include PF coils, but the PF loadings were applied on the PF support brackets • Weight of TF and PF coils are also included.

11. Von Mises Stress Plots excluding Umbrella Structure Max. stress Max. stress in support leg Vacuum Loads Dead Loads

12. Von Mises Stress Plots excluding Umbrella Structure Max. stress Max. stress EM, Vacuum and Dead loads EM Loads

13. Summary of Vacuum Vessel for Upgraded Loads Max. stress was found at the edge of port opening

14. Summary • EM load is the most crucial load case in the vacuum vessel design. • Because of symmetry in the EM load, ring bar can be used to reduce the in-plane load caused by the outer TF legs. • Tie rod can minimize the deformation of the ring bar and take the out-of-plane loading without causing bending moment in the vacuum vessel. • Provide struts between upper and lower PF4 and PF5 coils will effectively restrain the PF vertical force to the vacuum vessel. • The highest stress was found at the welded joint area between vacuum vessel and port, the allowable stress for welding should also be checked. • In the FEA model, the cross-sectional area of ring bar and tie rod is 4.0 in2 and 1.0 in2, respectively. • Other design considerations may include but not limit to: • Modify dimension and location of the ring bar and tie rod • Improve the outer TF leg stiffness • Reinforce the vacuum vessel • And ………..