If an electron gun creates a $10\space mA$ electron beam and each electron collides with a gas atom and creates an ion through impact ionization, can the ions then be accelerated with a separate negative voltage grid that is powered by a lower current capacity source but still maintains a $10\space mA$ current?
Basically, in the figure below - what is the maximum ion current accelerated by the $30kV$ grid?
(The gas pressure would be $10^{-5}$ Tor.)
Clarification: Is the ion current directly proportional to the current capacity of the 30kV grid?