High Voltage Transformer?

[Magnethos]

I need an output of 1 or 2 KVolts (no more).
I have tried with a microwave transformer, but it seems the transformer was broken.
I have thought about a flyback transformer, but it's too high for my project (20 KV)

So, I think the only solution is build one.
Do you know how can I build one? Have you schematics?

[Shanti]

Do you know how can I build one? Have you schematics?

LOL, forget it. Much easier and even cheaper buying one on Ebay. Well except you need a lot of power, or a special frequency.
What should be the current for your 1-2kV?

[AbbaRue]

MOT transformers rarely burn out or get damaged.
A good way to test them is to connect a low voltage transformer to the 120 V input side.
If you use a 6 Volt AC transformer the MOT should give you about 120 Volts output.
This is how you can test the MOT for the right leads. 
Usually the other lead is connected to the transformer core itself. \
Only one of the 3 wires coming from the HV winding is the HV output
the other 2 are for the Magnetron Filament and normally put out about 2 volts.
This 2 volts floats on the HV.
I'm quite sure your MOT will work if you file down a section of the core and connect one terminal there.
Then one of the other 3 wires is the other HV terminal. 
Hope this helps. 

I highly recommend using an isolation transformer for the 120 volt input as a current limiter. 
Microwave ovens always use some form of pulsed input going to the MOT as a current limiter.
Actually you could use the very circuit from the microwave for your device.
Just set the timer for how long you need the HV power and your all set.