Beam Profile Studies for a One Eighth Betatron Wavelength Final Focusing Cell Following Phase Mixed Transport

摘要

The focusing properties of a one eighth betatron wavelength focusing cell are used to determine to what extent a modification of the initial phase space distriution of an ion beam can alter the number density profile of the beam at the focal plane. It is shown that the main modification is to alter the natural l/r profile to include an off-axis peak. The relative difficulty with which the ion beams can be concentrated into this off-axis peak is then considered. Estimates of the source brightness (extraction ion diode source current density divided by the square of the microdivergence) required to deliver a given amount of beam current into a given annular region at the focal plane are derived.