Addendum -- Note that, should you manage to acquire a CRT, you may readily construct an 'accelerator PSU' with a salvaged LOPT and a 'half-Royer' driver circuit (construction time ≈ 10 minutes) --- Mind that you bring the CRT bias up slowly -- it is quite easy to 'burn' the phosphor with a stationary beam!

Best regards and good luck
HP

 

Also the problem with a monochrome TV is that the ray is being constantly scanned ans as much as I know the deflection yokes are part of the hv circuit of the cathode/anode

It is true that most TV horizontal/EHT 'sections' will not operate correctly without the yoke (Spec. the horzontal deflection coils) connected -- So...

If you wish to use the TV's EHT supply, merely remove the yoke from the neck of the CRT but leave it electrically connected to the circuit

Best regards
HP