Fast-switching elliptically polarized soft X-ray beamline X13A at NSLS

The X13A beamline at NSLS is dedicated to the generation and uses of fast-switching elliptically polarized soft X-ray radiation in the energy range from 250 to ~1600 eV. The source for this beamline is an elliptically polarized wiggler (EPW) that delivers linearly elliptically polarized soft X-rays at a switching rate, between right- and left-handed polarization, up to 100 Hz. The optical design is a spherical grating monochromator (SGM) that focuses and diffracts in plane orthogonal to the polarization switching direction. The X13A beamline scientific program is dedicated to spectroscopy and scattering studies of magnetism and magnetic materials. The fast-switching capability of the EPW enables the use of lock-in techniques, thereby greatly enhancing the detection sensitivity for small polarization-dependent signals.