I am building a simple Tesla circuit with a 50-100 kV transformer and capacitors, discharging through a spark gap into the circuit.
Is there anything besides a spark gap that would accommodate that high a voltage discharge?
The voltage has to be that high, so please don't try to dissuade that part of it. I simply need to know if there is a component that can accommodate that high a voltage.
There are vacuum and air and gas-filled relays that can handle higher voltages than that. They are expensive. Eg. Ross is one maker.
There are probably some hydrogen thyratrons. And stacks of semiconductors (for example, 20 5kV IGBTs) but they work with DC not HF AC.
And, of course, there is massive electrical switchgear, perhaps filled with über-greenhouse gas SF6.
If you don't care much about speed or arcing, and the current is low you could probably cob something together with a solenoid or an RC servo and contacts at the end of a G10 epoxy-glass rod or bar. I'm pretty sure I've seen some DIY items like that.
P.S. note this warning about X-rays emitted from vacuum relays in paticular: ".. over 15kV, the equipment should be shielded with lead that is at least 16 mm thick"
A hollow anode hydrogen thyratron will support both forward and reverse flows after triggering, allowing use with RF resonant circuits. However, you will still need to rectify the transformer output to DC for the capacitor charging, as the thyratron will only hold off DC of one polarity.
The more common alternative is to use a normal thyratron, but with a diode for the reverse flow.
Both options are described in the excellent E2V thyratron preamble app note.
A resistor would work... Just needs to be high voltage so you don't blow it apart:
Source: https://www.rhopointcomponents.com/product-category/components/resistors/high-voltage-resistors/
Make sure you get the correct wattage for the power you are dumping and for the voltage rating, use more in series (like 2x 50kV to get 100kV) .
