Y. N. Joshi

Ninth spectrum of iodine:l ix

The spectrum of iodine was observed in the region 300–80 A on a 10.7-m grazing-incidence spectrograph. The source used was a triggered spark. The earlier analysis of I ix has been revised and extended. Parametric level-fitting calculations support the analysis. Forty-three lines have been classified in this spectrum.

Eleventh spectrum of cesium: Cs xi

The spectrum of cesium has been photographed in the 300–80-A region on a 10.7-m grazing-incidence spectrograph using a triggered spark source. The lowest configuration in Cs xi is 4d9, and its 2D splitting has been found to be 19268 cm−1. Thirty-four levels of the 4d8 5p configuration have been established on the basis of their transitions to the 4d9 2D levels in the 135–115-A wavelength region. Parametric-level fitting calculations support the analysis. Forty-seven lines are now classified in this spectrum.

The Third Spectrum of Cadmium: Cd III

The third spectrum of cadmium was observed in the region 2100 A-500 A on a 6.65 m and a 10.7 m normal incidence vacuum spectrograph. The sources used were a triggered spark and a sliding spark. All levels of the 4d95s, 4d95p, 4d85s2, 4d96s, 4d95d, 4d97s and 4d96d configurations except the 1S0 levels in the 4d85s2, 4d95d and 4d96d configurations have been determined. The parametric level fitting calculations support the analysis. The new value of the ionization potential of Cd III, calculated from the 4d9ns series (n = 5, 6 and 7) is 302 200 cm-1 (37.46 eV). 266 lines have been classified in the Cd III spectrum in the region 2101 A-677 A, 155 of which are new lines.

Analysis of the 4d9 5d, 4d8 5s2 and 4d9 6s Configurations of In IV and Sn V

The spectra of indium and tin have been photographed in the region 1500 A-500 A on 10.7 m and 6.65 m normal incidence spectrographs. The sources used were a sliding spark and a triggered spark. The previous analysis of the 4d9 5d, 4d8 5s2 and 4d9 6s configurations in in IV has been extensively revised and the one in Sn V is completely new. All these levels are determined from their combinations with the levels of the 4d9 5p configuration. Interconfiguration interaction parametric calculations were carried out for both spectra and the calculated energy level values agree very well with the observed ones. 152 lines have been classified in In IV and 166 lines have been classified in Sn V.

Sixth and seventh spectra of arsenic: As vi and As vii

The spectrum of arsenic was photographed in the regions 1200–500 A and 300–100 A on a 6.65 normal-incidence and a 10.7 m grazing- incidence spectrograph, respectively. The source used was a triggered spark. These measurements enabled us to revise and extend the earlier analysis of As vi. In this spectrum we established all levels of the 3d10, 3d9 4s, 3d9 4p, and 3d9 4d configurations except 3d9 4d1S0. In addition the identification of the 3PO1, lPO1, and 3D°1 level’s in the 3d9 5p, 3d9 4f, and 3d9 5f configurations has led to a new value of the ionization limit of As vi: 974 000 cm−1 (120.7 eV). In As vii the earlier analysis of the 3d9−3d8 4p transitions has been revised and extended and the 3p5 3d10 2P levels were located. The parametric level fitting calculations support the analysis. 109 lines have been classified in As vi and 47 lines in As vii.

Ninth Spectrum of Bromine: Br IX

The spectrum of bromine was photographed on a 6.60 m and a 10.7 m grazing incidence spectrograph in the region 300-90 ?. The source used was a triggered spark. The ninth spectrum of bromine was analysed on the basis of 3d9-3d84p transitions between 125-104 ?. Parametric level fitting calculations support the analysis. 44 lines are classified in this spectrum. Some Br VIII lines appearing in this region have been accurately measured.

Analysis of the (5d(2)+5d6s)-5d6p transition arrays of Os VII and Ir VIII, and the 6s S-2-6p P-2 transitions of Ir IX

The spectra of osmium and iridium were photographed in the 300 Å to 1600 Å region on a 3 m normal incidence spectrograph using a triggered spark source. The (5d2 + 5d6s)–5d6p transition arrays of Os VII and Ir VIII were analyzed. All levels of these three configurations in both spectra have been established. There are 77 lines in Os VII and 71 lines in Ir VIII classified. The parametric least squares fitting calculations are used to interpret both spectra. The 6s 2S1/2–6p 2P1/2,3/2 transitions in Ir IX have also been identified.

Analysis of 4d 8 5s–4d 8 5p and 4d 9 –4p 5 4d 10 transitions in Sb vii

The spectrum of antimony was photographed in the region 600–2100 A on a 10.7-m normal-incidence spectrograph using a triggered spark source. All the levels of the 4d85s configuration, the unknown levels of the 4d85p configuration, and the 4p54d10 2P levels have been established. Least-squares-fitted parametric calculations support the analysis. An additional 177 lines have been classified in this spectrum.

The 5d2–5d6p Transitions in Au X and Hg XI

The spectra of gold and mercury were photographed in the 100–300 A region on grazing incidence spectrographs at the Antigonish, Troitsk and Gaithersburg laboratories. The source used in each laboratory was a triggered spark. The 5d2–5d6p transitions in Au X and Hg XI were analysed. All nine levels of the 5d2 configuration and eleven of the twelve levels of the 5d6p configuration of both spectra have been identified. The only unknown level is the 5d6p 3P0. 38 lines in the 233–292 A region in Au X and 38 lines in the 200–256 A regions in Hg XI have been classified. Hartree-Fock (HF) and Least-Square-Fitted (LSF) calculations interpret the spectra satisfactorily.

The analysis of the 4d8, 4d75s and 4d75p configurations of six-times ionized tin: Sn VII

The spectrum of tin was photographed in the 175 A-2000 A wavelength region using a triggered spark source. We have confirmed all nine levels of the 4d8 configuration and 86 of 97 levels of the 4d75p configuration reported earlier. The present investigation has led to establishing all levels of the 4d8 (9), 4d75s (37) and 4d75p configurations (110). Eight hundred and sixty-three (863) lines are now classified in the Sn VII spectrum. Least-square-fitted (LSF) and Hartree-Fock (HF) calculations were carried out for the three configurations.