Xray transformer under oil

Have been busy with the Xray transformer.
It's under oil now, the outgassing with vacuum took some time, lot's of bubbles :)

I tested the transoformer with 10V input, output was about 700V, I expected more, but maybe it's not that linear at low input voltages.

Negative HV supply for PMT's

The idea of making a high voltage with a DC-DC converter and a voltage multiplier can also be used to generate a negative supply for PMT's:

There is no need to use a P-channel mosfet, just reversing the diodes in the voltage multiplier reverses the polarity of the output.
The feedback circuit needs to be adapted to a negative output, when the PCB's for the positive supply are in, I will extend the design and make one ciruit board which can generate -3kV...+3kV with jumpers to switch polarity (changing in and out of the voltage multiplier and changing the feedback circuit).

10mm polycarbonate for the 85000V supply

Have been working on the (very small..) saw table today, sawing some polycarbonate sheet for the high voltage supply:

It's big enough for the Xray transformer which is going to be immersed in transformer oil (the real thing, 60kV/mm), to get the air out I will use vacuum, which will create a force of about 2900N on the biggest sides. The sides will be glued together with epoxy, the edges are 45 degrees.

I also got a preview of the circuit board for the neutron counter power supply (eurocircuits.nl):

Circuit board voor HV supply

The SNM-10 and another detector tube need about 1600V.
This is the circuit board:

Designed with Eagle.
The circuit is VERY DANGEROUS, it can deliver a few milliamps at 3kV, the capacitors are charged at 3kV. If you build this thing, make sure that you know what you are doing!
Eagle BRD file
Eagle SCH file