Voltage tripler using center tapped transformer

Okay so here's my scenario; I'm working on a high voltage experiment using a center tapped neon sign transformer (Primary-120, Secondary-15000, 30ma, 60hz) and need to rectify that into a negative DC voltage supply of about ~-30kV.
I've been trying to model my circuits on this website:https://www.falstad.com/circuit/ but nothing I do seems to work quite right..(maybe it's the simulator code?)

And if I were to use Microwave oven capacitors how many would I need to use? Each one is rated for 2100V and ~.8 to 1.0 uF.


My setup will resemble something like this:
110V wall -> Variac -> neon transformer -> tripling circuit -> -30kV to the inside of a vacuum chamber, +30kV grounded to the vacuum chamber itself

Have you googled 'voltage tripler' or 'cockcroft walton multiplier'?
Methinks you will need a helluva lot of caps if they're rated 2100V DC and each half secondary is 15000VAC.
Whatever, that's a seriously LETHAL lot of stored charge!

Oh, no. The total is 15000 ac and each half secondary will have 7500 ac.

I've only tried using villard cascades and I usually end up with either a x5voltage, x1 voltage, or the voltage will not stop rising until I end the simulation.. I'm beginning to think that the simulator's a bit screwey because I'm copying the circuit EXACTLY as i see it (but reversing the diodes because every circuit I find shows to rectify a positive dc voltage)
*shrug*

Simulation in LTspice works ok for me:-


Edit: Note voltage across C1 is ~11KV, voltage across the other components is ~22KV. So you would need a lot of those microwave caps strung in series, and strings connected in parallel, to make up just one of the caps shown in the sim. I've no idea what cap value is actually needed for each of C1-C3. The 1u value shown is purely fo sim purposes. I would advise against building this circuit unless you are aware of and accept the high voltage risks involved.