There's are some questions left. I reopen the thread. Please anybody stay away form non-technical contributions otherwise the thread will be finally closed.

Dimensions 110mm x 23.8mm 425 turns, same current, same gap in the center of 4cm.
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Bz at the center point is 0.36 T, similar range as previous designs.

Everybody can calculate ohmic losses, also winding thermal capacity and temperature rise at intermittent duty.

AC operation in series resonant circuit has been addressed in the recent discussion. I see two points that haven't been yet considered in this regard.
- A coil inductance of around 10 mH has been confirmed by different tools. You'll face a reactive voltage drop of > 15 kVrms at 5 kHz and 50 A.
- At 5 kHz, the coil resistance and respectively ohmic losses will increase due to skin and particularly proximity effect.