An LC ckt should do it, say we charge a cap to 60V and run it through an L to give a 400A peak, the Zo = 0.15 ohms
thus the L required = 0.0225 x C
larger components give a longer pulse, for 1 Hz say F = 1/ 2.pi SQRT(LC) and, 0.15 = SQRT ( L/C ) [Zo]
So 39.47 = 1 / LC and 0.0225 = L/C thus; 39.47 = 1 / ( 0.0225 C^2 ), thus C = 1.06F & L = 23.87 mH
[ check 1/(2.pi SQRT(L.C)) = 1Hz - tick ]
So a 100A SCR fired from a 1F cap, will give a pulse of 0.5 sec wide, 400A peak ( assuming no losses ) delivered via the 23.87mH coil ( 400A pk rated ) - at the end of which the current will be zero ( SCR will turn off ) and the cap volts will be zero - ready to re-charge to 60V - in this case ...
For your particular application a high power switch mode would work best with an SCR firing for the 100uS rise time,
pulse shaping LC circuits could also be employed