1. AWB 0410031 NSTX TF Flag Joint Design Review April 10, 2003 Art Brooks

2. AWB 0410032 Overview of TF Flag Analyses Thermal/Electrical Response ( ANSYS ) –Impact of Assumed Contact Resistance on Joint temperature and pulse length Inductive Effects ( SPARK ) Force Distribution ( SPARK )

3. AWB 0410033 ProE Model of TF Flag Geometry Epoxy layer (not present in latest design) Contact region Inner Leg Outer Turn

4. AWB 0410034 Geometry Imported to ANSYS and Meshed Higher order tetra elements used to auto-mesh irregular geometry 71/2 KA Current

5. AWB 0410035 Contact Region Modeled as finite thickness with equivalent resistivity

6. AWB 0410036 71 KA Waveform Driving Thermal Model Analysis assumes the Full I2t (6.5e9 a2s) based on.7 sec FT and L/R decay.

7. AWB 0410037 End Of Flat-Top Temperature Distribution assuming 6  in 2 Note: 6  in 2 Contact Resistance requires ~1.4 ksi contact pressure (Copper-on-Copper)

8. AWB 0410038 End Of Flat-Top Temperature Distribution

9. AWB 0410039 End of Pulse Temperature Distribution assuming 6  in 2

10. AWB 04100310 Temperature Peaks shortly after EOFT 176 C Flat top would have to be shortened to ~0.26 s to limit max temperature to 120 C at 6  -in2

11. AWB 04100311 Note: 4 micro-ohm-in2 Contact Resistance requires ~2.0 ksi contact pressure (Copper-on-Copper) End Of Flat-Top Temperature Distribution assuming 4  in 2

12. AWB 04100312 End Of Pulse Temperature Distribution

13. AWB 04100313 Flat top would have to be shortened to ~0.41 s to limit max temperature to 120 C at 4  -in2 Again, Temperature Peaks shortly after EOFT

14. AWB 04100314 End Of Flat-Top Temperature Distribution assuming 1  in 2 Note: 1  in 2 Contact Resistance expected with Silver Plated Joint and minimum 1 ksi press

15. AWB 04100315

16. AWB 04100316 End Of Pulse Temperature Distribution assuming 1  in 2

17. AWB 04100317 Temperature Peaks shortly after EOFT Flat top of 0.7 s achievable Max temperature less than 120 C at 1  -in2

18. AWB 04100318

19. AWB 04100319 Thermal Response Summary Peak Temperature at Joint occurs near threaded inserts, but localized Peak Temperature very dependent on Assumed contact resistance –Higher than expected contact resistance will force shortening of flat top at 6 kG –Full I2t achievable at 1  -in2 Bulk Heating of Flag small. Bulk Temperature not significantly impacted by assumption of contact resistance

20. AWB 04100320 Inductive Effects ANSYS analyses of Joint Heating assumed currents were resistively distributed SPARK Model used to assess current penetration Time constants for current penetration shown to be small

21. AWB 04100321 SPARK Model of NSTX TF Coil Geometry Only With Current Flow

22. AWB 04100322 t=.01 s t=. 1 s Current Penetration very quick Current penetrates from both sides of Lower Flag due to field from Upper Flag Current nearly resistively distributed

23. AWB 04100323

24. AWB 04100324 EM Force Distribution In Flags Spark Model Also Used to Determine EM force distribution in Flag from TF Field –Out of Plane forces from PF not repeated at this time. Forces Calculated for split flag configuration Resultant forces predominately vertical with 1/R distribution Forces not recalculated for solid flag, but –Vertical forces should still have same 1/R behavior and magnitude –Radial forces should be larger in flag and should work to keep joint closed

25. AWB 04100325 Note: Jump in loads at ends results from change in FEA mesh density

26. AWB 04100326 2 D distribution of IL Outer Turn Flag Forces

27. AWB 04100327 Summary Thermal distributions and EM loading provided as input to Structural Analysis being performed and presented by Irv Zatz