The aim of this work is study of the parameters affecting ion beam emerging from cold conical cathode ion source. The input discharge and output ion beam characteristics have been measured at different pressures using nitrogen and argon gases. The optimum distance between the ion exit aperture of the cathode and the movable copper ion collector plate has been determined using nitrogen and argon gases. The ion collector plate has been placed at different distances from the ion exit aperture of the cathode equal to 2, 3, 4, 4.5, 5, 5.5 and 6 cm respectively. It is found that the optimum distance between the ion exit aperture of the cathode and the ion collector plate equals 5 cm for high output ion beam current. At this optimum distance, the efficiency of the ion source reaches 28.3% and 21.3% using nitrogen and argon gases respectively. The divergence angle of the ion beam exit from the cathode aperture has been determined for each distance by measuring the ion beam diameter which obtained on the ion collector plate. It is found that at the optimum distance between the ion exit aperture of the cathode and the ion collector plate, a minimum divergence angle of the ion beam emerging from the ion source equal to 1.14º and 2.29º using nitrogen and argon gases respectively. Also the aspect ratio of the ion source, the ratio between the radius of the ion exit aperture of the cathode to the distance between the ion exit aperture of the cathode and ion collector plate, has been determined.

In this work, simulation of the singly charged argon ion trajectories for a variable plasma meniscus is studied with and without space charge for the triode extraction system by using SIMION 3D (Simulation of Ion Optics in Three Dimensions) version 7 personal computer program. The influence of acceleration voltage applied to the acceleration electrode of the triode extraction system on the shape of the plasma meniscus has been determined. The plasma electrode is set at +5000 volt and the acceleration voltage applied to the acceleration electrode is varied from -5000 volt to +5000 volt. In the most of the concave and convex plasma shapes, ion beam emittance can be calculated by using separate standard deviations of positions and elevations angles. Ion beam emittance as a function of the curvature of the plasma meniscus for different plasma shapes ( flat, concave and convex ) without space charge at acceleration voltage varied from -5000 volt to +5000 volt applied to the acceleration electrode of the triode extraction system has been investigated. The influence of the extraction gap on ion beam emittance for a plasma concave shape of 3.75 mm without space charge at acceleration voltage, Vacc = -2000 volt applied to the acceleration electrode of the triode extraction system has been determined. Also the influence of space charge on ion beam emittance for variable plasma meniscus at acceleration voltage, Vacc = - 2000 volt applied to the acceleration electrode of the triode extraction system has been studied.