Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

A Problem with ion generator

  1. Oct 29, 2018 #1
    I have to increase ion generation in a small ion accelerator but I have troubles to go over 20mA (1.27e17 ions/second). I can modulate up to 40 Mhz at 1kV. What ion generator it is recommended gor large ion flux?, I can work in pulse generation.
     
  2. jcsd
  3. Oct 31, 2018 #2

    Henryk

    User Avatar
    Gold Member

    it is hard to offer any suggestions not knowing what is your ion generator like. However, from my experience, your ion current might be limited by space charge.
     
  4. Nov 1, 2018 #3
    My actual "generator" not works. In the designs no more than 20mA can be done but heating a lot the copper to generate electrons. Pressure is in the 1-5Pa range.

    I would like use 2.4-3Ghz microwaves to heat hydrogen to ionic state instead of using hot OBe to emmit electrons and use electrons to ionize hydrogen. I can use solid state amplifiers or magnetron, but before buy and mounting I should like have the efficiency. The question is: what could be the efficiency of the RF?
    (I should use solid state amplifier or magnetron)

    About the space charge, it would help to introduce RF connected to the grid.

    Can be the output charge: Q=CV*f?
    Where C is the capacitance of the acceleration plates, f the signal frequency and V the voltage.
    I suppose there is a maximum frequency at that the ions can not reach the second plate at the output speed
     
    Last edited: Nov 1, 2018
  5. Nov 8, 2018 #4
    Are you making a sort of plasma thruster? Seems like Hall thruster upgrade to Vasimr or E-IMPAcT configuration.

    Typical ionization efficiency can be about 50% in these setups.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted