Formulation of spiral inflector design and its application to SF cyclotron

摘要

Ion trajectories through a spiral inflector are analyzed. In the case of a uniform magnetic field, it is shown that the central trajectory can be expressed as a simple analytical form, which includes all the inflector types already known. By using a curvilinear coordinate along the central trajectory, the equations of motion of non-central ions are modified to describe the ion motion in the transverse and longitudinal planes. A method is presented to expand the electric potential around the central trajectory to calculate the electric field to be used in the equations of motion. In the method, an electric potential thus obtained is used instead of the electric field, which guarantees the energy conservation of the ions through the inflector. Numerical studies have been carried out for design of an inflector for the SF cyclotron at the Institute for Nuclear Study, University of Tokyo. (author). (ERA citation 18:020870)