After thinking and reading about it I decided to try something that is not solid state.
I will make a relays auto oscillate like this:

https://youtu.be/WuG4nOyF99s
(without capacitor)

then the next step is this:

https://youtu.be/KIyZQLpQVqI
but again different.
the cap will be placed in series of the primary, and made series resonant. (not over the switch)

It will require tuning, and a relay that has NO diode.

this is based on Tesla's oscillator as seen in the Electric experimenter august 1919 article.
https://teslauniverse.com/nikola-tesla/articles/electrical-oscillators

Basically it is the mechanical version of what I now have solid state.

If tuned properly there will be NO spark as al the relay coil energy will pass as a single impulse through the series resonant primary.
This way, I hope I can make very high voltage impulses.

I'll try finding a fast relays but probably I will have to construct it myself.
This is because the switch needs ti be adjustable so I can tune the frequency.

maybe use reedswitch parts in combination with a coil with a ferrite core.

It needs to be as fast as possible. and the coil probably needs to be able to handle 64V dc at least.

I don't expect much from this project, it's more of a fun build, and to show it working without spark.

or Tesla will say like "I simply arranged a centrifugally rotating mercury make-and-break switch, lickety split." And I sigh. Oh just get the supercooled mercury from the... place :)

since relays work on low frequency, and car ignition coils also work on these frequencies, I will hook them up together, just like a tesla oscillator.

the trouble will be to tune the relay to the most efficient frequency, or the series cap.

I got the parts, so this should be fun (while I wait for my high voltage experiment parts)

my new relays, opened up. I think I am able to tune the normally closed contact.

I'll hook it up to the car ignation coil and see
Fun!

relay oscillator is around 300 cycles per second, without step up car ignition coil
tested with 19V battery (6v+12v in series)
giving - 200V impulses

couldn't find a  car ignition coil, but found another step up coil.
hooked up a 1.2uF in series with the primary of it, and placed it over de relay switch like a tesla oscillator.

Totally untuned, but it works!
800V on the secondary.

yellow is commutator of relays 50V/div
blue is high voltage probe on secondary, 200V per div

grounded the secondary on earth for a more stable signal.

getting 1000V on it

but whatbis the commutator doing? yellow shows a slow declining slope toward negative.
Ah! the impulse is completely gone. wait is that right?

probably the 1.2uF cap is to big and absorbs it.
very crude setup so...