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?

  • $\begingroup$ Is this an actual device, or a design idea? $\endgroup$
    – rob
    Nov 26, 2016 at 4:54
  • $\begingroup$ @rob, It's a design idea. Your thoughts? $\endgroup$ Nov 26, 2016 at 6:00
  • 1
    $\begingroup$ My guess is that if the gas is dense enough to act like a fluid, which you've suggested with your little cloud, then intra-fluid collisions will prevent any acceleration and you'll make a discharge tube. With a vacuum system to keep the gas at plasma densities, you might get some ions out. Thirty kilovolts is nontrivial. You should study some existing designs. Older documents sometimes assume less prior knowledge; Ramsey (very active midcentury, Nobel 1984-ish) is a good author to look for. $\endgroup$
    – rob
    Nov 26, 2016 at 17:20
  • $\begingroup$ @rob, thank you for the references, I'll look into those! As a side note I didn't intend the cloud to represent a high density of gas, only that gas was present; the operating pressure is probably somewhere in the $10^{-5}$ Tor range. $\endgroup$ Nov 26, 2016 at 17:47
  • $\begingroup$ Electron Beam Ion Sources $\endgroup$
    – user121904
    Nov 28, 2016 at 17:53


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