1. Update on voltage calculations
Tiina Salmi and Antti Stenvall,
Tampere University of Technology (TUT)
With contibution from Janne Ruuskanen and Valtteri Lahtinen, TUT
T. Salmi, TUT

2. Status
Last time showed preliminary voltage calculation for CosTheta and Block designs. Now have done checks and improvement to the code for more reliable results
Last time the magnet inductive voltage was divided evenly for all coil turns. Now the mutual inductance matrix is computed using a separete software and the inductive voltage is distributed to the turns according to their contribution to the total (differential) inductance.
The inductance calculation is thanks to our student Janne Ruuskanen – Team effort!
Details in appedix
I made a comparison with ROXIE quench module considering the costheta – The temperature and voltage distribution in the turns is in good agreement (inductive + resistive).
Worked together with Susana on this
More details in the appendix
I repeated the voltage analysis for all 3 design options. I will show the resulting voltages – they are smaller than in the presentation last time, not only because new inductance computations but also because of new designs.
Final slide has a summary table of the temperatures and voltages in all desings
T. Salmi, TUT

3. Simulation assumptions
Simulations using Coodi
Imag = 105% of Iop
tdelay = 40 ms (all coils quenched uniformly 40 ms after initial quench)
Impact of delay time also studied
Material properties based on NIST data (T and B dependency accounted)
Magnetic field map and inductance vs. Imag from ROXIE
Inductance distribution from ”Janne’s code”
Worst case hotspot in an LF cable with high field
Initial hotspot is small and doesn’t propagate: Negligible
effect on the voltage calculation
Effective self-inductance normalized to the maximum one
T. Salmi, TUT

4. Block, v26b Final temperature distribution
Worst case hotspot would be here, and reaches 308 K
(K)
T. Salmi, TUT

5. Block, v26b Peak potential to ground ~160 ms
This is for tdelay = 40 ms. But voltages are the same for tdelay = 10 ms. Only THS is lower (208 K).
Peak potential to ground ~160 ms
82 V btw adjacent turns
-1.2 kV to gnd
1.1 kV btw layers
+1.2 kV to gnd
(V)
T. Salmi, TUT

6. CosTheta, 16T_v28b-38-opt5d2 Final temperature distribution
Worst case hotspot would be here, and reach 328 K
(K)
T. Salmi, TUT

7. CosTheta, 16T_v28b-38-opt5d2 Peak potential to ground ~190 ms
This is for tdelay = 40 ms. But voltages are the same for tdelay = 10 ms. Only THS is lower (232 K).
Peak potential to ground ~190 ms
103 V btw adjacent turns
-1.4 kV to gnd
1.8 kV btw layers
(V)
T. Salmi, TUT

8. Common coil, v1h_intragrad_t2
Final temperature distribution
Worst case hotspot would be here, and reach 315 K
(K)
T. Salmi, TUT

9. Common coil, v1h_intragrad_t2
This is for tdelay = 40 ms. But voltages are the same for tdelay = 10 ms. Only THS is lower (230 K).
Potential to ground at ~200 ms
-2.3 kV to gnd
75 V btw adjacent turns
~3.3 kV between layers
(V)
T. Salmi, TUT

10. Summary (all at 105% of Iop)
Tdelay = 40 ms
T max (K)
V to gnd (V)
V turn-to-turn (V)
V layer-to-layer (V)
CC v1h_intragrad_t2
315
2300 75
3400
CosTheta v28b_opt5d2
328
1400
103
1900
Block
308
1200 82
1100
Voltages don’t depend on tdelay, but hotspot does:
NEXT: Analyze different delay distributions?
M Prioli just starting CLIQ simulations and analysis for the circuit
T. Salmi, TUT

11. Appendix
T. Salmi, TUT

12. Voltage comparison with ROXIE
T. Salmi, TUT

13. ms ms
Hotspot not shown, but is 203 K
At the end of ROXIE simulation (t = 247 ms), MIITs = 14.4 MAAs and Tmax = 195 K
Coodi ms: MIITs = 14.6 MAAs and Tmax = 203 K
T. Salmi, TUT

14. Costheta: Voltages between cables at 190 ms
Turn-to-turn (Laterally adjacent turns)
Layer-to-layer (vertically adjacent turns)
T. Salmi, TUT

15. CommonCoil v1h_intragrad_t2: Layer-to-layer voltages at ~190 ms
T. Salmi, TUT

16. CommonCoil v1h_intragrad_t2: Turn-to-turn voltages at ~190 ms
T. Salmi, TUT

17. Block_v26b: Voltages between cables at ~160 ms
Turn-to-turn (Laterally adjacent turns)
Layer-to-layer (vertically adjacent turns)
T. Salmi, TUT

18. IN
OUT
T. Salmi, TUT

19. T. Salmi, TUT

20. I in 1 1 9 2 6 4 7
I out 1 = I in 2 5 8 3
T. Salmi, TUT

21. T. Salmi, TUT

22. T. Salmi, TUT

23. T. Salmi, TUT