Kα 1 X-ray satellites of tantalum bombarded with fast nitrogen ions

Lewandowska-Robak

2004

Phys. Rev. A

Multiconfiguration Dirac-Fock calculations with the inclusion of the transverse (Breit) interaction and QED corrections have been carried out for Pd, Sn, Tb, Ta, Pb, and Th in order to obtain positions and intensities of various electric dipole, electric quadrupole, and magnetic dipole K x-ray diagram lines and of their KL 1 satellites. Theoretically constructed stick spectra have been presented together with synthesized spectra (the sum of the Lorentzian natural line shapes) for each studied element. Taking into account the existence of an L-shell hole in the 2s or 2p subshell, the effect of additional L-shell ionization on the shapes and structure of the K x-ray spectra has been examined. It has been observed that generally with increasing atomic number Z the shapes of particular satellite line groups tend to become smoother and to differ less from the shapes of appropriate diagram lines. Relations between the values of energy shifts of various satellite lines for each element and the changes of these relations with Z have also been studied. Additionally, the relations between the intensities of different diagram lines for each element have been systematically analyzed, likewise the changes with Z of the role of particular diagram lines. This study can be helpful in reliable and quantitative interpretation of many experimental K x-ray spectra of Pd, Sn, Tb, Ta, Pb, and Th induced in collisions with various projectiles.

Section: Introductionmentioning

confidence: 99%

Structure of variousKL1x-ray satellite lines of heavy atoms

Lewandowska-Robak

2004

Phys. Rev. A

“…As is commonly known [33,34,38], in comparison with the KL 0 M 1 satellite lines, the KL 1 M 0 satellite contribution is easier to identify in the measured K x-ray spectra. There are some KL 1 M 0 bands which should be clearly separated in the experimental spectra and thus the easiest to extract, yet the MCDF calculations would still be helpful in the interpretation of the spectra and getting the information about the L-shell ionization probability.…”

Section: Extraction Of Satellite Contributions In Experimental Spectramentioning

confidence: 82%

Possibility of extraction of various KL⁰M¹and KL¹M⁰satellite lines in the x-ray spectra of medium-Zand heavy atoms

J. Phys. B: At. Mol. Opt. Phys.

Lewandowska-Robak

2006

Predictions about the shapes of the K x-ray spectra of medium-Z and heavy atoms have been made on the basis of the results of theoretical multiconfiguration Dirac–Fock calculations (with the inclusion of the transverse Breit interaction and QED corrections) for various KL0M1 x-ray satellite lines of Pd, Tb, Ta and Th. The construction of theoretical stick and synthesized (the sum of the Lorentzian natural line shapes) K x-ray spectra (including also diagram and KL1M0 satellite lines) has enabled foreseeing such details of experimental spectra as the overlapping and visibility of particular groups of lines. The energy regions possibly best for the extraction of the satellite contributions in the measured K x-ray spectra have been indicated for each studied element. The effect of additional single ionization of the different subshells of the M shell on the structure and shapes of the spectra of various K x-ray lines has been investigated in detail for Pd, Tb, Ta and Th. It has been found that in the KL0M1 satellite spectra the shapes of the bands mainly resemble the shapes of the corresponding K x-ray diagram lines (but they are wider than the latter). For each element, the biggest average energy shifts with respect to the diagram lines are observed for a given kind of the KL0M1 lines mostly in the case of removing a 3p electron in the initial state, whereas the smallest shifts are caused by removing a 3d electron. Our study can enable the correct quantitative interpretation of the K x-ray spectra of different multiply ionized medium-Z and heavy atoms (induced in collisions with light or heavy ions) and can be instrumental in planning various new experiments involving the determination of the M- and L-shell ionization probability.

“…This method has been applied to many studies on the L-shell ionization probability in collisions of target atoms with Z < 30 . Since 1987 it has also been applied to studies of target atoms (with Z > 40) bombarded by various light and heavy projectiles [25][26][27][28][29][30][31][32][33]. Recently this method has been extended to determine the M-shell ionization probability in collisions with light projectiles [34][35][36][37] and, with the help of extensive multiconfiguration Dirac-Fock (MCDF) calculations, to determine the M-shell ionization probability in collisions with heavy projectiles [38,39] and with 4 He 2+ ions [40].…”

Section: Introductionmentioning

confidence: 99%

Simultaneous L- and M-shell ionization of a⁸⁰Se target deduced from the analysis of energy shifts and relative intensities of K x-ray lines induced by various projectiles

J. Phys. B: At. Mol. Opt. Phys.

Raj

Dhal

et al. 1999

Average energy shifts of K and K x-ray satellite lines and K/K intensity ratios have been experimentally evaluated for a 80Se target bombarded by various projectiles with atomic numbers in the region 3 Zp16 at a given projectile energy of 3.3 MeV/u. The data have been analysed using an approach, based on the results of extensive single-configuration Dirac-Fock (DF) calculations, performed within the multiconfiguration DF method for various distributions of holes in subshells of a 80Se ion. This provides information about the average number of holes in various subshells of 80Se ions at the time of emission of the K x-ray lines. The primary average number of L- and M-shell holes in a 80Se target produced at the moment of collisions with projectiles and the average ionization probabilities per electron for L and M shells have been deduced by means of a simple statistical scaling procedure which accounts for all processes that modify the number of L- and M-shell holes prior to the K x-ray emission. It has been found that the average ionization probabilities per electron for L and M shells increase considerably with Zp2. For larger Zp the average ionization probability per electron is significantly higher for M shells than for L shells. On the other hand, for small Zp the ionization probability per electron seems to be slightly higher for L shells than for M shells. Moreover, the dominant role of the simultaneous multiple ionization of L and M shells accompanying the ionization of a K shell has been observed for projectiles with Zp>3.