Beamline Description

Monochromator and beamline optics

The SpectroMicroscopy beamline comprises the monochromator and the microscope joined at the pinhole "P". The source is the U12.5 undulator mounted at the 3.2 section of ELETTRA and shared with the VUV Photoemission beamline. The beamline is based on a variable angle spherical grating monochromator with  gratings optimized for photon energies engaged. The monochromator uses a variable included angle in the diffraction process by the simultaneous rotation of a spherical grating (SG) and a plane mirror (PM) in front of it, defining a (virtual) movable entrance slit (Padmore design). A set of three gratings covers the energy range of 20-310 eV: 20-62 eV (grating 1), 60-155 eV (grating 2), and 125-310 eV (grating 3).

Besides the monochromatisation action, the beamline performs a predemagnification of the X-rays by forming an intermediate focused image of the source at a pinhole "P" placed at the beginning of the microscope section of the beamline (size = 13 µm H x 9 µm V) by means of a pair of focusing (HFM and VFM) and refocusing (HRM and VRM) mirrors placed before and after the monochromator.