UNIFORM TARGET IRRADIATION BY CIRCULAR BEAM SWEEPING

A circular sweep of the beam over a large target for making a uniform irradiation zone is suggested. The scan pattern is an untwisted spiral for a continuous beam or a family of concentric circles for a bunched beam. The deflection voltage is provided by RF cavities with orthogon al transverse fields shifted in time by pi/2. The amplitude of the def lection voltage as a function of time and the optimal beam scan freque ncy with respect to the RF frequency of the accelerator are given. The considered method of target irradiation can be useful in different ap plications of charged particle beams including microfilters production and transmutation of nuclear wastes where a large amplitude of the de flection voltage and a high uniformity of irradiation are required.