Spectrum of scandium in the energy region52 625–54 046 cm−1

Abstract

The Rydberg and autoionization Rydberg spectrum of scandium via intermediate state [Ar] $3d4s4p\text{ }{^{2}F}_{5/2}$ have been measured in the energy region $52\text{ }625--54\text{ }046\text{ }{\text{cm}}^{\ensuremath{-}1}$ using two-laser resonance excitation. Four autoionization Rydberg series are observed. Eigenquantum defects ${\ensuremath{\mu}}_{\ensuremath{\alpha}}$ and transformation matrices ${U}_{i\ensuremath{\alpha}}$ are calculated from first principles by relativistic multichannel theory within the framework of multichannel quantum defect theory, while the dipole matrix elements ${D}_{\ensuremath{\alpha}}$ are obtained by comparing with experimental data. With these parameters ${\ensuremath{\mu}}_{\ensuremath{\alpha}}$, ${U}_{i\ensuremath{\alpha}}$ and ${D}_{\ensuremath{\alpha}}$, Rydberg and autoionization Rydberg spectrum of scandium are calculated and the experimental peaks are then clearly assigned. More specifically, one autoionization Rydberg series is converged to ${\text{Sc}}^{+}$ $3d4s\text{ }{^{3}D}_{3}$, the other three series are converged to ${\text{Sc}}^{+}$ $3d4s\text{ }{^{1}D}_{2}$, and one autoionization state converging to ${\text{Sc}}^{+}$ $3{d}^{2}({^{3}F}_{2})$ and/or ${\text{Sc}}^{+}$ $3{d}^{2}({^{1}D}_{2})$ are assigned. In addition, the Fano parameters ${E}_{r}$, $q$, and $\ensuremath{\Gamma}$ for some of these states are fitted and analyzed.