Present status of the beam test of the deflection element for dispersion control

A deflection electrostatic deflector has been designed for an ion storage ring. This electrostatic deflector, together with a dipole magnet makes a condition where a dispersion function of ion beams is controlled at a bending section. For this purpose, the electrostatic deflectors are designed, and the deviation of the calculated field from the ideal value is less than 0.1%, within 2.5 mm from the beam axis. The effect of a hole for laser injection is also considered. After modification of the structure of the electrodes, the deviation near the hole is improved. We planned the experiment to verify the effect of dispersion control by using the first constructed deflection element. An ion beam will be produced from an ion source and injected into the deflection element directly. Adjustment of an ion source and the setup of the experiment are also considered. (author)