The Glassman unit is currently supplying a positive potential, we need a negative potential. The tag on the back panel shows +/- 10kV:
But inside the unit, in the high voltage section is this label:
I’m going to talk to Glassman tech today.
So I spoke to Glassman tech, and to get a negative potential for this unit I would need to swap out the entire high voltage section with a negative potential version. This power supply likely came with a negative unit, but it was not resold to me. I asked Glassman if they could make a negative unit for me. Might not be possible because the unit is so old. Should know more soon.
Spoke with Bob Glassman. For $370 they can convert the unit to a negative polarity and refurbish it.