I was thinking about triggering a TinyLogic one-shot that will be 4 KV off ground.
How about a surface-mount inductor on one side of a PCB, and another on the opposite side, as a transformer? Whack the primary with a big fast pulse, and it might make enough on the other side to fire a 1G123. Gotta try it, I guess.
(Remember to cut away the ground plane, dummy!)
Any other ideas? I want sub-ns jitter, so optos and official couplers would be too slow.