Experience from LHQ Coil 01

1. Experience from LHQ Coil 01 Miao Yu 03/07/2013

2. Outline • Cable Pop Strand • Coil Parts • Curing Pressure and Control • Other DR • Summary

3. Pop Strand Winding tool was used for both IL and OL

4. Wedge Insulation • The sleeve was cut in the length of the wedge before curing with the binder • The sleeve became loose at the end

5. Inner Layer Coil Parts

6. Cable damage • When push the inner layer LE and RE saddles, the tips cut through insulation • Cable was damaged • Plasma coating was removed • Coating pros: • The coated parts give us better dielectric strength • Coating cons: • The coating surface is much more abrasive than the metal surface. It is difficult to monitor if the part cuts through the insulation and damage the cable or not, until coating is also damaged.

7. IL Curing • 120 g Ceramic Matrix Binder was applied to the IL without comparing HQ coil • 44 g binder was used for HQ IL • Scale up: 142 g HQ: 928.22 mm, LHQ: 2985.62 mm

8. IL After curing

10. Outer Layer Coil Parts

11. OL after Curing • 140 g Ceramic Matrix Binder was applied to the OL without comparing HQ coil • 65.4 g binder was used for HQ OL • Scale up: 209 g HQ: 938.9 mm, LHQ: 2997.65 mm

12. LE Saddle

13. RE Saddle

14. RE Saddle Coating thickness • The tip of the spacer is ~10 mil thinner

15. Parts Modification Before plasma coating, • Open up all the pin holes to 0.25” (light press fit the dowel pin) in the pole pieces. • Open 1 mm to the slits in the outer layer spacers. • Grind more material off the bottom area of the tips for IL and OL saddles • Fit the part during winding, remove more • Fit the part after curing, remove less

16. Mid-Plane Shim 60 mil cut off from mid plane • 70 mil shim was installed along the whole coil, gaining 10 mil gap for the coil at mid plane • However due to the design of the saddle, we might over compressed the saddles. For next coil, install 70 mil shim along the coil, and 65 mil alone the saddles

17. Curing Pressure and Control • Gap was measured between the platen and the curing mold on both side • Coil stress is calculated assuming all force goes to the coil winding tooling (no force on curing mold)

18. Pole Gap Inner layer LE RE • Before curing, total gap size decreases by 0.301 mm from 12.192 mm (2.4%) • After curing, total gap size increases by 0.198 mm from 12.192 mm (1.6%) • Before reaction, total gap size is 9.86 mm, 3.3 mm/m (2.986 m inner layer coil length)

19. RE LE Outer layer • Before curing, total gap size decreases by 0.301 mm from 12.192 mm (2.4%) • After curing, total gap size increases by 0.198 mm from 12.192 mm (1.6%) • Before reaction, total gap size 9.35 mm, 3.1 mm/m (2.999 m inner layer coil length) Inner layer 20 turn, 30 lbs/ turn, 600 lbs Outer layer 26 turn, 35 lbs/turn, 910 lbs ¼ inch screw, maximum shear stress 31 ksi, much lower than the material yield strength.

20. Lifting the coil

21. Coil preparation for shipping

22. Other DR • Coating chips off around slit area • IL LE saddle splice block do not align properly • 1/4" key stock was used instead of ¼” dowel pin. • Voltage tap VT-B8 (OL LE NT Pole turn) was broken after curing by accident. The thickness of VT is thinner than before.

23. Summary • Winding tool was used. 9 pop strand events, 4 of them could be avoided. • The sleeve insulation was glue to the wedge by two ways (a. glue the end; b. glue the whole wedge). The first one is better and will be used for next coil. • When install saddles during winding, be careful if they are not fit well. The procedure should be easily push as far as we can, and after curing they will fit. From next coil, more material will be removed from the bottom tip area before coating. • All the pin holes in the pole should be opened up before coating. The slit in the outer layer spacers should be opened up by 1 mm before sending out for coating. • Less amount of curing binder was used. The scale up amount from HQ coil should be used for next coil • For next coil, install 70 mil shim along the coil and 65 mil alone the saddlesto over compress the cable by 5 mil. • Before coating, verify the alignment between LE saddle and splice block. • Need more voltage tap. Pay more attention on the installed VT.