Calculation of parameters of axial-symmetrical electrostatic lenses in the matching channel of a linear accelerator

The paper deals with a numeric calculation of a matching channel of axially symmetric lenses. The motion of stationary ion beam in electron optical system consisting of two axially symmetric lenses is considered. Volume charge distribution and particle trajectory are found by solving jointly the equations of electromagnetic field and motion of large particles by the method of sequential approximations. The proposed technique allows to solve the problems related to the selection of optimal geometric and potential parameters of the matching channel. The results of calculations performed for 40 keV protons; 0, 25, 50, 100 mA beam currents and 0.12 cm x mrad and 0.066 cm x mrad values of initial reduced emittance are discussed 4 refs., 4 figs