Improvement of Beam Divergence by Emission Profiles with Better Homogeneity

Ion beam divergence is influenced by the emission profile of the beam; inhomogeneities can stimulate the transition from the stabilizing diocrotron mode to the detrimental high divergence ion mode. Applied fields for homogeneous beam emission profiles, which differed in strength and tilt, were designed for the KALIF Bappl diode. Experiments were performed on KALIF with these fields. They resulted in the lowest divergences ever measured with this diode. This proves, that the beam emission profile is a controllable key variable to improve the focusing properties of the beam