Electrode-structural effects on characteristics of ion beams produced by inverse reflex tetrodes

Pulsed ion beams are extracted from two kinds of inverse reflex tetrodes, and their characteristics are investigated in detail. When the size of the tetrode is enlarged and a triple point is formed on the beam side, extracted beam currents are doubled. Current neutralized proton beams with a peak energy of 180 keV are obtained with the extraction angle of about 2–3 degree. The value of proton beam current is 400 A, and the maximum flux density is 40 A/cm
²
. Virtual cathode formations and electron reflexing effects are also assured. These tetrode characteristics may be described by the existing reflex theory [6].