Effects of electrode geometry on the ion beam extraction of closed drift type anode layer linear ion source

Closed drift type anode layer linear ion source was investigated with focusing on the electrode geometry effects on ion beam emission and anode layer formation. In the electrode geometry, the discharge gap between anode and cathode plays an important role to control anode layer formation as well as electron generation. When the discharge gap is increased from 2 to 3 mm, the ion current density was enhanced from 0.9 to 1.35 mA∕cm(2). Computational simulation by using an object oriented particle in cell showed that the discharge volume was extended due to enhanced electron generation and the electric field at the anode layer was enhanced from 1.32 to 1.52 MV∕cm.