Horizontal Emittance Reduction on a Synchrotron Radiation Light Source with a Robinson Wiggler

Abstract

The performance of synchrotron light facilities are strongly influenced by the photon beam brightness, that can be further increased by reducing the beam emittance. A Robinson Wiggler can be installed in a non-zero dispersion straight section to reduce the horizontal beam emittance. It is composed of an array of magnets of alternated polarities, whose both magnetic field and gradient are of opposite signs. It provides a compact solution to reduce by 50% the horizontal emittance. However, it increases the energy spread by 40%. The concept of the Robinson Wiggler (RW) is described here, the first experimental observation of the Robinson effect in a synchrotron light source on the transverse and longitudinal beam properties by the means of four existing undulators is presented and the impact on the photon flux density is studied.