Voltage Multipler with change capacitor value ratio
It is not the ratio of C that multiplies , rather the clamp DC added to the Vpp .. triplets etc cascade more diode caps
Pro Bono info
There are limits as diode drops (insignif for HV) and cap ESR adds so attenuation from leakage limits multiplier.
More accurately it ought to be called a Clamp Adder as Vpp is added to each stage. But for 1 stage of 2 diodes and 2 caps  it is x2.  , or N/2 +1 multiply Vpp input for N diodes,Caps or X stages + 1 input multiplier * load/leakage attenuation
Somewhat like inductive transformers, C ratio is called a capacitive transformer so you get /2 boost on each cycle peak until it reaches ,maximum (unless loaded)
C transformers are used in some HV bushings to divide HVAC down from 1 pF say to 10nF is 1e4:1 voltage divider for sensing on AC without DC load.