Capacitor, Cornell-Dubilier 940C20W1K-F 1.0uF, 2000V
These poly capacitors are the best you can use for Tesla coils period! They can be used for both solid state (DRSSTC) and spark gap Tesla coils. These capacitors can take an enormous beating and keep coming back for more!
These are used for the primary capacitor arrays in the Reference Design 3.0 DRSSTC Tesla coil system.
Click here for the datasheet (PDF)
Note: The photo above is a generic photo for this capacitor product line.