BL4B Varied-Line-Spacing Plane Grating Monochromator for Molecular Soft X-Ray Spectroscopy

▼Description
  The beamline BL4B equipped with a varied-line-spacing plane grating monochromator (VLS-PGM) was constructed for various spectroscopic investigations in a gas phase and/or on solids in the soft X-ray range. Three holographically ruled laminar profile plane gratings with SiO₂ substrates are designed to cover the photon energy range from 25 to 800 eV. The gratings with groove densities of 100, 267, and 800 l/mm cover the spectral ranges of 25–100, 60–300, and 200-1000 eV, respectively, and are interchangeable without breaking the vacuum. Fig. 1 shows the absolute photon flux for each grating measured using a Si photodiode (IRD Inc.), with the entrance- and exit-slit openings set at 50 and 50 m, respectively. The maximum resolving power (E/E) achieved for each grating exceeds 5000.
  There is no fixed endstation on this beamline. A small vacuum chamber equipped with an electron multiplier (EM) detector is available. Soft X-ray absorption spectra of solid samples are usually measured by means of the total electron yield method using EM, and the partial fluorescence yield method using a silicon drift detector (SDD).

▼Technical Data