I came across the following design of a nuclear fusion reactor (electrostatic configuration):
It works as follows:
- A vacuum is created in the spherical stainless steel chamber.
- A small amount of deuterium gas is let into the vacuum chamber.
- A DC voltage of 150kV is applied across the tungsten ring inside the vacuum chamber to start fusion.
My question is, given the high voltage across the tungsten ring inside the vacuum chamber, and its close proximity to the conducting stainless steel shell, how does this design avoid current flowing across the stainless steel chamber?
Is the partial vacuum sufficient to prevent an arc between the tungsten ring and the shell, or would this design rely on the shell not being located near a ground?
If this is due to the low gas density inside the vacuum chamber, which laws/calculations could be used to verify that the current cannot cross the gap between the tungsten ring and the stainless steel chamber?