Monday, June 11, 2012

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.

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