To collect the correct pulse capacitor, it is necessary to pay attention to the dielectric. Dielectric is better to use multi-layer. The capacitor must be recruited from the sections. The sections are connected in series, thus increasing the operating voltage. With a parallel connection, increase the capacity.
The distance from the edge should be at least 10mm. The thickness of the dielectric should not exceed 100 micrometers, so a thicker dielectric will have a higher probability of breakdown. It is also necessary to use oil, pre-drying and making degassing of the dielectric.
Working in the pulsed mode, the capacitor experiences great overloads, so the period of the service is not great. When working at maximum voltage, the number of bits will be only a few thousand.
A photo of my work. Soon the test.
Read next
From @leonid96