NUMERICAL SIMULATION OF 3-D ION BEAM OPTICS BY BOUNDARY-FITTED COORDINATE TRANSFORMATION METHOD.

Ion source devices must be operable with a wide range of beam currents and acceleration voltages. In order to realize ion sources with high beam transmission under such conditions, it is indispensable to evaluate the 3-D ion beam focus characteristics. Hence, there is a strong need for an accurate analysis method. For the accurate simulation of ion extraction from ion sources, the plasma boundary surface geometry must be determined exactly and ions must satisfy initial conditions (i. e. initial velocity and emission angle on the surface) in the calculation. The present approach uses a boundary-fitted coordinate transformation method so as to treat the complicated geometries of electrodes and a deformed plasma boundary surface.