| Popis: |
The emission spectra of the A 2 Π–A′ 2 Δ transition of LaS have been reinvestigated using spectra recorded with the 1-m Fourier transform spectrometer of the National Solar Observatory at Kitt Peak. Sixteen bands involving the vibrational levels v ′ = 0–5 and v ″ = 0–5 of the Δ v = −1, 0 and 1 sequences of the A 2 Π 3/2 –A′ 2 Δ 5/2 sub-band have been rotationally analyzed to derive an improved set of spectroscopic constants for the two states. Rotational perturbations have been observed near J = 171.5, 155.5, 134.5, 112.5, 85.5, and 43.5, respectively, in the v = 0, 1, 2, 3, 4, and 5 vibrational levels of the A′ 2 Δ 5/2 state. These perturbations are caused by interaction between the A′ 2 Δ 5/2 ( v ) and A′ 2 Δ 3/2 ( v + 2) levels of the lower state. |
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