Determination of the populations of metastable levels in Gd vapor by a laser spectroscopy method during electron-beam evaporation of the metal

The relative populations of the levels of the a⁹D⁰. term in the electron configuration 4f⁷5d 6s² of atomic gadolinium were determined. Atomic vapor was obtained by evaporation of Gd with an electron beam. The distribution of the populations of all five levels of the a⁹D⁰ term differed considerably from the Boltzmann form.