Update on voltage calculations Tiina Salmi and Antti Stenvall, Tampere University of Technology (TUT) 11.3.2016 With contibution from Janne Ruuskanen and Valtteri Lahtinen, TUT T. Salmi, TUT

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

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

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

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

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

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

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

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

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

Appendix T. Salmi, TUT

Voltage comparison with ROXIE T. Salmi, TUT

Coodi @247 ms ROXIE @247 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 simulation @247 ms: MIITs = 14.6 MAAs and Tmax = 203 K T. Salmi, TUT

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

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

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

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

IN OUT T. Salmi, TUT

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

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