Here two Cockcroft-Walton voltage multipliers (one +ve, the other -ve) generate 60kV each in opposite polarities,
so the potential difference between the two is around 120kV.
The multipliers are supplied with 6kV of high frequency AC from a ferrite transformer driven by a Mazzilli ZVS circuit.
Each multiplier uses 10 30kV 30ma diodes and 10 capacitors (9 1nF 30kV and 1 2nF 30kV).
The output current is limited by 6 10M 10kV resistors on each multiplier.