Present status of the analyses of the first and second spectra of uranium (U I and U II) as derived from measurements of optical spectra

Spectroscopic and Theoretical Investigations of UF and UF+

“…Unfortunately, as Figure 2 demonstrates, an intense transition of UO occurred at the same energy and overlaid the UF band, thus preventing the recording of a clean high-resolution LIF spectrum of UF in this region. Consequently, only a lower-resolution REMPI spectrum was recorded for this transition, which 36 f These states belong to 5f 3 7s6dδ ion core. Figure 3 was collected with the ScanMate Pro laser tuned to the Q-branch of [18.6]3.5-X(1)4.5 transition.…”

Calculated oscillator strengths for the strongest lines of cosmochronological interest in the visible spectrum of singly ionized uranium (U II)

“…In their critical compilation related to actinides, Blaise & Wyart (1992) listed some preliminary U II energy levels, using the emission lines listed by Steinhaus et al (1971) and Palmer, Keller & Engleman (1980), thus updating the previous estimates published by Brewer (1971). An uranium hollow-cathode Fourier transform spectrum between 1800 and 42 000cm −1 was then combined with previous visible and ultraviolet spectra by Blaise et al (1994) who were able to determine the numerical values for 354 and 809 energy levels belonging to the four odd configurations 5f 3 7s 2 , 5f 3 6d7s, 5f 3 6d 2 , 5f 4 7p, and to the six even configurations 5f 4 7s, 5f 4 6d, 5f 2 6d 2 7s, 5f 2 6d7s 2 , 5f 3 7s7p, 5f 3 6d7p, respectively.…”

Spectrum of Singly Charged Uranium (U II) : Theoretical Interpretation of Energy Levels, Partition Function and Classified Ultraviolet Lines

“…The possibility for correcting the J-value for E exp = 13,695.737 was thus examined. Indeed, while a J = 11/2 attribution can be justified by only one unique transition with a J = 13/2 even level, a J = 9/2 value is supported by 16 lines of [7] and by two unidentified lines from the infrared line list of [14] that fit transitions with J = 7/2 even levels. Table 4 collects the transitions supporting the present assignation of a J = 9/2 for this level.…”

“…wl Ritz : Ritz wavelength calculated with experimental energies from [6]; wl exp : experimental wavelength ; ∆wl = wl exp − wl Ritz ; wn exp : experimental wavenumbers; ∆wn = wn exp −(E even − E odd ). LA: line already assigned as U II transition in [7], as: asymmetrical line, c: complex line shape, p: line resolved on the plate, but perturbed by a close line, b: broad line, ? : line given by [12] as U III without classification, IV : this line could be blended with a strong U IV line, D: line with double identification, T: line with triple identification, #n: line number in Figure 1.…”

“…The critical compilation of energy levels and spectra of actinides published in 1992 by Blaise and Wyart [3] provided preliminary tables of energy levels of both parities in U II. The compilation of U II was based on emission data from Steinhaus et al [7] and on new FTS measurements by Palmer et al [8]. In particular, energy values of the lowest levels of configurations involving 5 f , 6d, 7s, 7p electrons were reported, thus updating the previous estimates by Brewer [9].…”