La−binding energies by analysis of its photodetachment spectra

Abstract

This study reinterprets an earlier experimental photoelectron kinetic energy spectrum of the negative ion of lanthanum [A

Photodetachment spectroscopy of quasibound states of the negative ion of lanthanum

“…As previously reported by our group [1], the lowest energy threshold observed over this energy range is a sharp s-wave threshold due to detachment from the La -(5d6s is not distinctive in the spectrum of Fig. 2; this finding is consistent with the calculations of Pan and Beck, which showed a much smaller cross section for photodetachment from 1 D2 o to 2 D5/2 than to the ground state 2 D3/2 [13]. It is worthwhile in the present paper to compare our previously measured binding energy of the La -1 D2 o state of 335.6(8) meV [1] to subsequent theoretical [5] and experimental [11] values.…”

“…In addition, the fixed-frequency photoelectron spectroscopy experiments by Covington et al [8] and Lu et al [11] yield some information about relative photodetachment channel strengths. On the theory side, Pan and Beck have performed calculations of photodetachment cross sections from Laat two discrete photon energies: 337 meV to assess photodetachment as a loss mechanism from the 3 D1 o upper-level of the potential laser-cooling transition [3]; and 2410 meV [13] to re-interpret the earlier photoelectron spectroscopy data of Covington et al [8]. However, none of the previous studies have investigated the photon energy dependence of the continuum photodetachment spectrum or the quasibound resonance structure of La -.…”

Accurate electron affinity of atomic cerium and excited states of its anion*

“…However, strong electron correlation effects do allow the existence of a few bound excited states of some atomic lanthanide anions. For example, La − [1,2] and Ce − [1] possess 15 and 32 bound states, respectively. In particular, it has been confirmed experimentally that La − , [3,4] Ce − , [5,6] Os − , [7,8] and Th − [9,10] even have bound states with opposite parities.…”

“…This is the prerequisite for laser cooling as a strong electric dipole cycling transition is needed. [11][12][13][14] The electronic configuration of the ground state of Ce atom is [Xe]4f5d6s 2 . The strong correlation effects caused by the unusual chemical bonding of 4f electrons of Ce atoms turn many Ce compounds into strongly correlated materials.…”