Investigation of highly excited states of samarium

Abstract

Highly excited even parity states of the samarium atom in the range between 34104 and 39155 cm -1 have been studied by the method of one color three photon resonance ionization spectroscopy. The energies and total angular momenta of 342 states have been determined. Seven new even parity states of samarium have been discovered.

Three-Photon Resonance Ionization Spectroscopy of Excited Even-Parity States of the Samarium Atom

“…Taking the aforesaid into account, it is of interest to analyze even-parity states of the samarium atom located at energies below 34100 cm −1 , but using an excitation scheme different from those applied in the cited experiments [2,10,13]. In this work, which continues our previous researches [7,12], the method of single-color three-photon resonance ionization spectroscopy was used for the determination of the energies and the total angular momenta of excited evenparity states of the samarium atom, which are located in the energy interval 32620-34092 cm −1 .…”

“…When the lasing frequency was changed, the laser radiation intensity in the interaction region was maintained at a constant level of 9 × 10 7 W/cm 2 . This level makes it possible to reveal the majority of peaks associated with two-photon transitions in the dependence + ( ) [12].…”

“…A method for identifying the resonance structure in three-photon ionization spectra and determining the energies and total angular momenta of even-parity states was described in works [7,12] in detail. Its essence consists in combining the peaks observed in the dependence + ( ) into groups associated with the two-photon excitation of the same upper evenparity levels from different lower levels of the main term 7 .…”

“…When identifying the levels with ≥ 1, only groups containing three or more maxima were analyzed. Note that, in the case of two maxima, the accidental coincidence of the frequencies of observed maxima and the frequencies of possible two-photon transitions is highly probable [7,12]. Groups with two peaks were analyzed only with respect to the excitation of levels with the total angular momentum = 0, for which only two-photon transitions from the initial levels 7 0 and 7 2 are allowed [14].…”

“…GOMONAI, A.N. GOMONAI, 2018 two-step (two-color) [1-4, 6, 8-11, 13] and two-photon (single-color) [5,7,12] schemes of level excitation.…”