Rapidly-modulated variable-polarization crossed-undulator source

The needs of research teams in many disciplines now mandate the construction of rapidly modulated variable-polarization crossed-undulators for polarization-sensitive experiments. Such a source is being proposed for the Aladdin storage ring at the Synchrotron Radiation Center (SRC) to provide arbitrary polarization, modulated at 10 Hz, with a first harmonic tunable from 8-40 eV. An outline for an entire system´s design is presented. The crossed-undulator design uses two planar undulator sections, each producing linearly polarized radiation, rotated with respect to one another by 90 degrees about their common longitudinal axis, and variably phased along the same axis, as illustrated. The proposed system will result in a comprehensive facility for the production and utilization of variably polarized radiation.<>