Beamline Description

The resolution

The resolution of the monochromator can be experimentally measured by measuring the broadening of gas absorption lines by means of a Samson type ionization chamber, placed between the exit slit stage and the refocusing chambers. The resolution is calculated as the ratio between the photon energy E and the FWHM width of the Gaussian curve, shown in the Figures below. The resolution of the monochromator E/DE for the grazing incidence channels at a given energy depends on the vertical slits aperture and on the deviation angle, while for the GNIM depends only on the slit aperture. The experimental resolution has been experimentally determined at about 400 eV by measuring the K-shell vibrational states 1s->p* of biatomic nitrogen, at about 867 eV  by the K-shell excitations of atomic Ne, at 60 eV the autoionizing states of double excited He for the grazing incidence channels, the Rydberg states of atomic He at about 20 eV for the GNIM channel.

Experimental resolution of G1200 channel (High flux configuration)

Experimental resolution of G1200 channel (Higher order rejection configuration)

Experimental resolution of G1800 channel (High flux configuration)

Ultima modifica il Martedì, 23 Febbraio 2021 14:12