Study on the penning ion source with cold cathodes

The ion current in the beam has been established experimentally to depend on the anode diameter dsub(a) in a constant magnetic field. For the anodes studied, the ion current [n the beam has been found to reach the first (main) maximum at dsub(a)=13 mm, and the second one - at dsub(a)=25 mm, the ion current to the discharge current ratio being equal 26% and 6% correspondingly. The location of maximums does not depend on the anode voltage Vsub(a) or pressure p, whereas their values vary with either Vsub(a) or p changes. It is concluded that with the increase in the anode diameter the ionization region shifts from the discharge axis to the anode