somewhat different Marx generator configuration

 I saw something similar to this arrangement in a commercial generator, but that one had more space between the stages. Note that the inter-stage insulator forms an additional small capacitor across each stage gap.  As each stage erects, this additional capacitance must be charged before the gap overvolts.  With care in spacing, dielectric material, and some attention to field shaping at the edges, that capacitance may be sufficiently low that the additional stages-per-unit-length of generator housing make it a worth while dodge.  I need to go on a paper-reading bender again, see if anyone has done something similar.

fast Marx generator progress

Since one of the things I need to test the recently completed switch is a very fast, very high voltage trigger source; and since I was already working on a fast coaxial Marx anyway, it just became a high priority again. As a reminder, "fast" in this case means (hopefully) much less than 1uS and hopefully << 10nS; and "high voltage" means not less than 60kV, although I am hoping to stuff enough stages into the housing I have on hand to allow for 80kV or 100kV. If I can find more caps with appropriate specs before I begin final construction, I might even manage 100kV from only eight stages. Stuffing more than eight stages into a housing only 4" x 19" is proving problematical. If I unexpectedly obtain longer housing and insulator tubes before I begin assembly, I'll think about changing my plans.

I accomplished a fair amount of work on the housing this weekend. Because I am not yet set up to weld aluminum, I am still making the bloody housing out of copper and brass which can be silver-soldered to get a flange onto the ground end at the very least. Given that this is a voltage, high impedance, low current device, it doesn't NEED to be made out of those materials, I'm simply working with what is most readily available and has the lowest cost - for me, given the resources at my disposal - to achieve.

I've nearly finished the closure flange for the ground end, through which pass two gas ports (gas & relief), two SHV connectors for charging voltage and trigger, and possibly a small but high quality pressure gauge if I can find room.

I would like to have flanges on both ends, but the amount of effort and cost to make another identical flange for the hot end seems prohibitive for now.