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M-shell satellite structure of W X-ray emission lines
Radiation Physics and Chemistry 61 (2001) 401–403
M-shell satellite structure of W X-ray emission lines A.M. Vlaicua,*, Y. Itob, K. Taniguchia, T. Mukoyamab, T. Bastugc a
Osaka Electro-Communication University, 18-8 Hatsu-Cho, Neyagawa, Osaka, 572-8530 Japan b Institute for Chemical Research, Kyoto University, Gokasho, Uji 611-0011, Kyoto, Japan c JAERI-Tokai Research Establishment, Naga-kun, Ibaraki, 319-1106 Japan
Abstract The M-shell satellite structure of W X-ray emission lines excited by electron bombardment is investigated by a high resolution single crystal spectrometer, and the obtained structure is further compared with calculated transition energies obtained by the Relativistic Density Functional method. The transition hole states situated in the N- and O-shellsFdue to Coster–Kronig transitionsFcorrespond to the parts of the spectra situated in the close neighbourhood of the diagram transition (0.7–4.4 eV). r 2001 Elsevier Science Ltd. All rights reserved. Keywords: X-ray emission; Satellite; M-shell; Double-hole; Coster–Kronig transitions
1. Introduction
2. Present investigation
The spectra of X-ray emission lines have a complex structure due to the presence of additional holes in the outer shells, which accompany the main transition. The additional holes are called spectator holes, and the induced transitions which are slightly shifted, usually to the higher energy side of the diagram line, are called satellite lines. Although the origin of these satellite lines can be explained by various mechanisms, there are few experimental studies which actually consider the presence of the satellite lines in the spectra. Compared to L-shell X-ray emission spectra, the spectra of M-shell X-ray spectra has a far more complicated structure, as the spectator holes can be created by an increased number of channels, such as shake-off, Auger, Coster–Kronig and super-Coster– Kronig transitions. In the present work, we attempt to identify the contribution of the Coster–Kronig induced satellites in the M-shell spectra of W, both experimentally and theoretically.
The W M a; b emission lines, generated by electron bombardment from a rotary target X-ray generator, were measured by a high resolution single crystal spectrometer, using a RAP(400) single crystal. The spectra (see Fig. 1), fitted to Lorentzians shows a satellite structure which can be observed on the higher energy side of the corresponding diagram line in a energy range of 2–18 eV. In order to identify the transition of the satellites, the transition energy was calculated for the case of double-hole states with the spectator holes in the N- and O-shell, which are mainly produced by Coster–Kronig transitions. The Discrete Variational Density Functional method was used for the calculation. The matrix elements of the secular equation derived from the single particle Kohn–Sham equation are evaluated numerically using the integration scheme of Boerigter et al. (1988) in the modified version of Bastug et al. (1995). The transition energies for the double-hole state emission lines are presented in Table 1. Analysing Table 1, we observe that all the satellites transitions which find their origin in a single spectator-
*Corresponding author. Fax: +81-72-825-4690. E-mail address: [email protected] (A.M. Vlaicu).
0969-806X/01/$ - see front matter r 2001 Elsevier Science Ltd. All rights reserved. PII: S 0 9 6 9 - 8 0 6 X ( 0 1 ) 0 0 2 7 9 - 1
402
A.M. Vlaicu et al. / Radiation Physics and Chemistry 61 (2001) 401–403
Fig. 1. W M a 1; 2 emission spectra.
Table 1 Calculated transition energies of Ma1 [3d5/2]–[4f7/2] and Ma2 [3d5/2]–[4f5/2] diagram lines and satellite lines originating from by a single N- or O-shell spectator hole Transitions Ma2 [3d5/2]–[4f5/2]
Energy (eV) 1747.77
DE (eV) 0.00
Transition Ma1 [3d5/2]–[4f7/2]
Energy (eV) 1749.93
DE (eV) 0.00
Spectator hole N1 [4s1/2] N2 [4p1/2] N3 [4p3/2] N4 [4d3/2] N5 [4d5/2] N6 [4f5/2] N7 [4f7/2] O1 [5s1/2] O2 [5p1/2] O3 [5p3/2] O4 [5d3/2] O5 [5d5/2]
Energy (eV) 1749.76 1749.29 1750.58 1749.10 1749.12 1749.77 1752.19 1748.56 1748.65 1748.25 1748.08 1749.08
DE (eV) 1.99 1.52 2.81 1.33 1.35 2.00 4.42 0.79 0.88 0.48 0.31 1.31
Spectator hole N1 [4s1/2] N2 [4p1/2] N3 [4p3/2] N4 [4d3/2] N5 [4d5/2] N6 [4f5/2] N7 [4f7/2] O1 [5s1/2] O2 [5p1/2] O3 [5p3/2] O4 [5d3/2] O5 [5d5/2]
Energy (eV) 1752.19 1751.66 1752.80 1751.17 1751.44 1752.07 1752.19 1750.86 1750.64 1750.14 1750.09 1751.21
DE (eV) 2.26 1.73 2.87 1.24 1.51 2.14 2.26 0.93 0.71 0.21 0.16 1.28
hole in the N- or O-shell are very closely situated to their diagram line, from 0.7 to 4.4 eV, whereas the experimental results show both close satellites (0.7–5 eV), as
well as far satellites (7–16 eV). At this stage, we have to consider the possibility of M-shell spectator holes, which can be produced by Auger and/or super-Coster–Kronig
A.M. Vlaicu et al. / Radiation Physics and Chemistry 61 (2001) 401–403
transitions. These double-hole states should produce satellites which are energetically further apart from their parent line, due to the fact that both holes are in the same principal shell. These satellites should also have much lower intensity, which would explain the long, low intensity tail toward higher energy side of the spectra. In the near future, transition energies for M-shell and multiple spectator hole states will be calculated.
403
References Bastug, T., Sepp, W.-D., Kolb, D., Fricke, B.D., Velde, G.Te, Baerends, E.J., 1995. All-electron Dirac-Fock-Slater SCF calculations for electronic and geometricstructures of Hg2 and Hg3 molecules. J. Phys. B 28, 2325. Boerigter, P.M., Velde, G. Te and Baerends, E.J., 1988. Threedimensional numerical integration for electronic structure calculations. Int. J. Quantum Chem. XXXIII, 87–113.
M-shell satellite structure of W X-ray emission lines A.M. Vlaicua,*, Y. Itob, K. Taniguchia, T. Mukoyamab, T. Bastugc a
Osaka Electro-Communication University, 18-8 Hatsu-Cho, Neyagawa, Osaka, 572-8530 Japan b Institute for Chemical Research, Kyoto University, Gokasho, Uji 611-0011, Kyoto, Japan c JAERI-Tokai Research Establishment, Naga-kun, Ibaraki, 319-1106 Japan
Abstract The M-shell satellite structure of W X-ray emission lines excited by electron bombardment is investigated by a high resolution single crystal spectrometer, and the obtained structure is further compared with calculated transition energies obtained by the Relativistic Density Functional method. The transition hole states situated in the N- and O-shellsFdue to Coster–Kronig transitionsFcorrespond to the parts of the spectra situated in the close neighbourhood of the diagram transition (0.7–4.4 eV). r 2001 Elsevier Science Ltd. All rights reserved. Keywords: X-ray emission; Satellite; M-shell; Double-hole; Coster–Kronig transitions
1. Introduction
2. Present investigation
The spectra of X-ray emission lines have a complex structure due to the presence of additional holes in the outer shells, which accompany the main transition. The additional holes are called spectator holes, and the induced transitions which are slightly shifted, usually to the higher energy side of the diagram line, are called satellite lines. Although the origin of these satellite lines can be explained by various mechanisms, there are few experimental studies which actually consider the presence of the satellite lines in the spectra. Compared to L-shell X-ray emission spectra, the spectra of M-shell X-ray spectra has a far more complicated structure, as the spectator holes can be created by an increased number of channels, such as shake-off, Auger, Coster–Kronig and super-Coster– Kronig transitions. In the present work, we attempt to identify the contribution of the Coster–Kronig induced satellites in the M-shell spectra of W, both experimentally and theoretically.
The W M a; b emission lines, generated by electron bombardment from a rotary target X-ray generator, were measured by a high resolution single crystal spectrometer, using a RAP(400) single crystal. The spectra (see Fig. 1), fitted to Lorentzians shows a satellite structure which can be observed on the higher energy side of the corresponding diagram line in a energy range of 2–18 eV. In order to identify the transition of the satellites, the transition energy was calculated for the case of double-hole states with the spectator holes in the N- and O-shell, which are mainly produced by Coster–Kronig transitions. The Discrete Variational Density Functional method was used for the calculation. The matrix elements of the secular equation derived from the single particle Kohn–Sham equation are evaluated numerically using the integration scheme of Boerigter et al. (1988) in the modified version of Bastug et al. (1995). The transition energies for the double-hole state emission lines are presented in Table 1. Analysing Table 1, we observe that all the satellites transitions which find their origin in a single spectator-
*Corresponding author. Fax: +81-72-825-4690. E-mail address: [email protected] (A.M. Vlaicu).
0969-806X/01/$ - see front matter r 2001 Elsevier Science Ltd. All rights reserved. PII: S 0 9 6 9 - 8 0 6 X ( 0 1 ) 0 0 2 7 9 - 1
402
A.M. Vlaicu et al. / Radiation Physics and Chemistry 61 (2001) 401–403
Fig. 1. W M a 1; 2 emission spectra.
Table 1 Calculated transition energies of Ma1 [3d5/2]–[4f7/2] and Ma2 [3d5/2]–[4f5/2] diagram lines and satellite lines originating from by a single N- or O-shell spectator hole Transitions Ma2 [3d5/2]–[4f5/2]
Energy (eV) 1747.77
DE (eV) 0.00
Transition Ma1 [3d5/2]–[4f7/2]
Energy (eV) 1749.93
DE (eV) 0.00
Spectator hole N1 [4s1/2] N2 [4p1/2] N3 [4p3/2] N4 [4d3/2] N5 [4d5/2] N6 [4f5/2] N7 [4f7/2] O1 [5s1/2] O2 [5p1/2] O3 [5p3/2] O4 [5d3/2] O5 [5d5/2]
Energy (eV) 1749.76 1749.29 1750.58 1749.10 1749.12 1749.77 1752.19 1748.56 1748.65 1748.25 1748.08 1749.08
DE (eV) 1.99 1.52 2.81 1.33 1.35 2.00 4.42 0.79 0.88 0.48 0.31 1.31
Spectator hole N1 [4s1/2] N2 [4p1/2] N3 [4p3/2] N4 [4d3/2] N5 [4d5/2] N6 [4f5/2] N7 [4f7/2] O1 [5s1/2] O2 [5p1/2] O3 [5p3/2] O4 [5d3/2] O5 [5d5/2]
Energy (eV) 1752.19 1751.66 1752.80 1751.17 1751.44 1752.07 1752.19 1750.86 1750.64 1750.14 1750.09 1751.21
DE (eV) 2.26 1.73 2.87 1.24 1.51 2.14 2.26 0.93 0.71 0.21 0.16 1.28
hole in the N- or O-shell are very closely situated to their diagram line, from 0.7 to 4.4 eV, whereas the experimental results show both close satellites (0.7–5 eV), as
well as far satellites (7–16 eV). At this stage, we have to consider the possibility of M-shell spectator holes, which can be produced by Auger and/or super-Coster–Kronig
A.M. Vlaicu et al. / Radiation Physics and Chemistry 61 (2001) 401–403
transitions. These double-hole states should produce satellites which are energetically further apart from their parent line, due to the fact that both holes are in the same principal shell. These satellites should also have much lower intensity, which would explain the long, low intensity tail toward higher energy side of the spectra. In the near future, transition energies for M-shell and multiple spectator hole states will be calculated.
403
References Bastug, T., Sepp, W.-D., Kolb, D., Fricke, B.D., Velde, G.Te, Baerends, E.J., 1995. All-electron Dirac-Fock-Slater SCF calculations for electronic and geometricstructures of Hg2 and Hg3 molecules. J. Phys. B 28, 2325. Boerigter, P.M., Velde, G. Te and Baerends, E.J., 1988. Threedimensional numerical integration for electronic structure calculations. Int. J. Quantum Chem. XXXIII, 87–113.