I would like to make a post about what is a Henrie...

A value of 1 Henrie inductance really mean that if you apply 1v for 1 second to it assuming it has no resistance at all will charge to 1 amperes.. the time constant gives you also this same result L/R if you divide L/R both being 1 you get 1 second but this is another thing... this is the time will take for the current to drop to % of its value. it really takes 5 times constants to the current really disapear..

back to the henrie...

if you apply 40kv for 1ns into a 40mh coil should allow the current to go to 1ma...

now comes the interesting part... the inductance changes when you add a core,,

but how does a core work?

why we say it saturates..

actually the core material under no applied field has its maximum permeability... when we apply a pulse the core start to decrease this permeability to the point where in saturation is minimal...

the number of turns needed to be able to apply such a voltage on a coil if the coil on a core must be thought because otherwise the core would saturate way before you need without you perceiving it

so is necessary to calculate the maximum webber and find the turns that would be required by that route..

basicaly minimum turns will be the applied voltage * pulsetime /area/bmax

for example my cores has 1 square inch and that is 6,45E-4 m2 = 0,0254m*0,0254m =0,000645m2

so for this voltage using this core like this and this time 1ns i would need only less than 1 turns..

not really sure if the core would even respond in such fast time..

the permeability should need be realy big to provide such inductance with only one turn of wire...