The structure of the forbidden transition λ = 647.5 nm (6p3 4 S°3/2-6p3 2D°5/2) in Bi I has been completely analyzed by means of a Fourier-transform spectrometer. In addition to the 12 components corresponding to ΔF = 0, ±1, two components corresponding to ΔF = ±2 have been observed for the first time to our knowledge. From the intensity calculations, it is estimated that the admixture of electric-quadrupole radiation is about 20%, in agreement with the earlier theoretical calculations of Garstang [J. Res. Nat. Bureau Stand. Sect. A 68, 61 (1964)] The A and B constants are also calculated and compared with earlier results. The value of the level 2D°5/2 has been recalculated to be 15437.51 ± 0.01 cm−1.
© 1984 Optical Society of America
S. George, J. H. Munsee, and J. Verges, "Hyperfine structure in the 6p3 4S°3/2-6p3 2D°5/2 647.5-nm forbidden transition in Bi I," J. Opt. Soc. Am. B 1, 320-322 (1984)