The Ca I absorption spectrum in the vacuum ultraviolet: excitation of the 3p-subshell

1977 ◽  
Vol 357 (1688) ◽  
pp. 77-102 ◽  
Keyword(s):  
Absorption Spectrum ◽  
Vacuum Ultraviolet ◽  
Electron Excitation ◽  
Single Electron ◽  
Hartree Fock ◽  
Simultaneous Excitation ◽  
Ultraviolet Excitation

The Ca I absorption spectrum between 300 and 800 Å (41-10 eV) has been photographed revealing at least 125 new lines. All the stronger lines are identified by comparison with Hartree-Fock calculations. In addition to single electron excitation of the 3p-subshell there is clear evidence of a simultaneous excitation of the 4s valence subshell and a 3p-subshell electron. The more important processes of multi-electron excitation are indicated. The general case of 3p → 3d excitation in elements Z ═ 18 to 28 is discussed and is illustrated by plots of the effective central potentials for 3d wavefunctions derived from the Hartree-Fock results.

The Sr I absorption spectrum in the vacuum ultraviolet: excitation of the 4p-subshell

1981 ◽  
Vol 377 (1771) ◽  
pp. 431-448 ◽  
Keyword(s):  
Absorption Spectrum ◽  
Electron Impact ◽  
Electron Spectrum ◽  
Vacuum Ultraviolet ◽  
Rydberg Series ◽  
Hartree Fock ◽  
Ultraviolet Excitation

The Sr I absorption spectrum between 300 and 800Å|| has been photographed, and nearly 200 new lines have been revealed. Two methods are used to analyse the spectrum. First, comparison with multiconfiguration Hartree-Fock calculations is used to identify first series members and, secondly, simplified Lu-Fano plots are used to order other lines into Rydberg series. Identifications are also provided for many lines of the Sr 4p-subshell ejected-electron spectrum, excited by electron impact (White et al. 1979). In particular eighteen SrII levels are identified.

The K I absorption spectrum in the vacuum ultraviolet: 3p-subshell excitation

1975 ◽  
Vol 346 (1647) ◽  
pp. 539-553 ◽  
Keyword(s):  
Absorption Spectrum ◽  
Vacuum Ultraviolet ◽  
Hartree Fock

The K I absorption spectrum has been photographed in the range 700–350 Å, revealing at least 140 new features. Comparisons with Hartree–Fock calculations are used for interpretation. All observed features can be attributed to excitation of the 3p-subshell and an assignment–often tentative–is given to nearly every observed feature.

The simultaneous excitation of two electrons in atomic cadmium

1978 ◽  
Vol 362 (1708) ◽  
pp. 129-144 ◽  
Keyword(s):  
Absorption Spectrum ◽  
Energy Levels ◽  
Final State ◽  
Electron Synchrotron ◽  
Continuum Source ◽  
Hartree Fock ◽  
Simultaneous Excitation ◽  
Background Continuum ◽  
Configuration Mixing ◽  
First Time

A new investigation of the Cd I absorption spectrum, with an electron synchrotron as a background continuum source, has revealed 110 new features between 400 and 1100 Å. The new lines are identified by comparison with Cd II energy levels, Hartree-Fock calculations and the Zn I absorption spectrum in the same energy region (Mansfield & Connerade 1978). All are attributable to simultaneous excitation of two electrons, observed for the first time in cadmium. At longer wavelengths the spectrum is due to the excitation of both valence electrons and at shorter wavelengths it is due to excitation of one valence, and one 4d-subshell electron. The detailed analysis suggests that, as in zinc, double-excitation occurs through a final state configuration mixing process similar to conjugate shake-up.

The absorption spectrum of Ag I in the vacuum ultraviolet

1978 ◽  
Vol 361 (1706) ◽  
pp. 379-398 ◽  
Keyword(s):  
Absorption Spectrum ◽  
Synchrotron Radiation ◽  
Variational Method ◽  
Theoretical Prediction ◽  
Ab Initio ◽  
Absorption Spectra ◽  
Vacuum Ultraviolet ◽  
Rydberg Series ◽  
Hartree Fock ◽  
Doubly Excited

The absorption spectrum of Ag I between 550 Å and 1590 Å has been investigated by using synchrotron radiation as the source of continuum. Over 50 new transitions are reported, nearly all of which can be classified into Rydberg series due to excitation of one electron from the 4d subshell. Identifications are made by comparison with previous studies of the arc spectrum as well as with absorption spectra of related elements. Ab initio Hartree-Fock calculations have revealed the importance of treating 5s 5p 1 P based levels by a separate variational method. Doubly excited configurations are also found, but, in contrast to a previous theoretical prediction, double vacancy production within the 4d subshell is not found to be significant for Ag I.

Inter-subshell correlations and simultaneous ejection of two photoelectrons in the absorption spectrum of Ga I

1977 ◽  
Vol 354 (1679) ◽  
pp. 511-527 ◽  
Keyword(s):  
Absorption Spectrum ◽  
Single Electron ◽  
Core Hole ◽  
Simultaneous Excitation ◽  
Electron Transitions ◽  
Valence Electrons ◽  
First Time

The absorption spectrum of gallium vapour between 320 and 1000 Å has been investigated for the first time; more than 90 transitions have been detected between 440 and 660 Å. The most intense of these are attributed to excitation of an electron from the 3d subshell but many features occur through simultaneous excitation of two valence electrons and derive their intensity from correlations with the single electron transitions. The concept of at 3d-core ‘hole’ in Ga I is shown to break down near the threshold for simulaneous ejection of two photoelectrons.

The Ca I absorption spectrum in the extreme ultraviolet: excitation of the 2p subshell

1976 ◽  
Vol 348 (1652) ◽  
pp. 143-151 ◽  
Keyword(s):  
Absorption Spectrum ◽  
Extreme Ultraviolet ◽  
Hartree Fock ◽  
Ultraviolet Excitation ◽  
Quantum Defects ◽  
First Time

The Ca I absorption spectrum has been photographed between 10 and 120 Å for the first time. At least seven discrete features – all attributable to excitation of the 2p subshell – have been observed. Identifications are made by comparison with Hartree–Fock calculations. The Hartree–Fock results also support an explanation of the irregular quantum defects and remarkable breadths of the lines assigned to the 2p→3d transition.

Absorption spectra due to excitation of a single 3p electron and simultaneous excitation of two electrons in Rb I

1976 ◽  
Vol 348 (1655) ◽  
pp. 539-552 ◽  
Keyword(s):  
Absorption Spectrum ◽  
Absorption Spectra ◽  
Absorption Lines ◽  
Hartree Fock ◽  
Simultaneous Excitation

A modification of the vapour containment technique has enabled the X-u. v. absorption spectrum of Rb I vapour to be recorded at higher vapour densities than previously attainable. Twenty seven new transitions have been detected. These include a group of resonances extending up to 5eV above the 3d thresholds and absorption lines attributed to excitation of the 3p subshell. The analysis of Mansfield & Connerade (1975 a ) is extended in the light of the new data and of further comparisons with Hartree-Fock calculations.

The Tl I absorption spectrum in the vacuum ultraviolet

1976 ◽  
Vol 350 (1660) ◽  
pp. 47-60 ◽  
Keyword(s):  
Absorption Spectrum ◽  
Energy Range ◽  
Vacuum Ultraviolet ◽  
Simultaneous Excitation

New observations of the absorption spectrum of neutral Tl, in the wave­length range 320‒1300 Ň are reported. Earlier observations and an analysis by Connerade (1972) are confirmed and extended. Present obser­vations include 142 new transitions, mostly outside the previous energy range, which have been classified, mainly within the scheme proposed by Connerade (1972). The absence of some series due to excitation of one electron from the 5d subshell is noted and is attributed to the occurrence of strong series due to simultaneous excitation of two electrons.

The K I absorption spectrum in the vacuum ultraviolet: 2p-subshell excitation

1975 ◽  
Vol 346 (1647) ◽  
pp. 555-563 ◽  
Keyword(s):  
Absorption Spectrum ◽  
Vacuum Ultraviolet ◽  
Hartree Fock ◽  
Detailed Interpretation ◽  
First Time

The K I absorption spectrum between 10 and 120 Å has been photographed for the first time, revealing eight discrete features between 40 and 43 Å. These features are all attributed to excitation from the 2p subshell and a detailed interpretation is achieved after comparison with Hartree–Fock calculations.

On the outermost d-subshell absorption spectra of Ge I and Sn I

1977 ◽  
Vol 357 (1688) ◽  
pp. 103-115 ◽  
Keyword(s):  
Absorption Spectra ◽  
Atomic Structure ◽  
Electron Excitation ◽  
Double Ionization ◽  
Ionization Threshold ◽  
Single Electron ◽  
Discrete Structure ◽  
Hartree Fock ◽  
First Time

The quenching of single electron excitation channels first reported in the outermost d-subshell spectra of In I and Ga I is investigated here for the elements Sn I and Ge I. The absorption spectra of Sn I and Ge I between 320 and 1000 ŧ have been observed for the first time. Discrete structure is attributed to the excitation of a single electron from the outermost d-subshell and identifications of the upper configurations are obtained by comparison with Hartree-Fock calculations, the atomic structure being computed in approximate LS coupling. There is evidence that the 4d spectrum of Sn I is affected by the proximity of the double ionization threshold.

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