Pulse width for the 1st horn is 0.4 ~ 0.8 ms.

H.V. is 1.2~0.6 kV.

I’m not sure if this pulse width is wide enough for the current to spread out.

It should be checked.

For the leakage of the field, I don’t understand what is the problem.

Inside outer-conductor, the field is anyway proportional to 1/r?

(Horn inductance will be increased.)