A CHANGE in magnetic field near a conductor induces current flow in the conductor.
A CHange in current flow in a conductor induces a magnetic field around it.
So; As DC Voltage causes no CHANGE in current flow, EMI (Electro Magnetic Interference) is not a problem here.
100 uA @ 7500 Volts is very little. The spark will burn you though.
= ??? A @ 30 000 Volts. Im guessing 1 or 2 mA?
Boundry layer:
If air is blowing over a solid surface; How fast are the air molecules, directly in contact with the solid's surface moving?
Very little, if at all.
The layer of molecules just above is moving a bit faster, and so on....
If an electron flies from on electrode to the other you can be sure its really moving!
115 000 Km/h comes to mind, but I could be wrong.
These electrons bump into air molecules on the way over; imparting some of their velocity to them and inducing the airflow.
You can be pretty sure that when these electrons crash into the surface of the other electrode the WILL dislodge the air molecules in the boundry layer, in dramatic fashion!
This will allow other, cooler air to come directly into contact with the surface to be cooled.
ie: NO BOUNDRY LAYER!
If I were to try this I would use water cooling, Exos type;
The radiator would be one electrode with very thin wire as the other;
The thin wire @ -30 000 Volts and the Rad. @ 0 Volts (Earthed) Still = a Potential Difference of 30 00 V.
Electrics from an old CRT monitor can be used for this.
Now it starts getting technical!
So wont try to explain now.
The Rad. could not have any fins.
This would negate airflow....
This disadvantage would be offset by Zero boundry layer...
I would also still earth the water block...
So the only advantage really, to doing this, would be silent cooling.
( Assuming you watercooled everything)
And perhaps the calm electron thing...
The Negativly Ionised air would be nice too... (Google Air Ionizers)