No abstract available

[en] On the high energy side of the unresolved doublet Lγ₂₃in the L spectra of some elements, a satellite L_γ2,3' has been reported in literature, which has been ascribed to the transition L₁M_x − M_xN_2,3, on the basis of energy considerations alone, by earlier workers. In the present work, apart from energy, calculations have also been done for the intensity of the probable transitions which may give rise to the satellite in the elements from ₄₀Zr to ₄₇Ag and from ₅₇La to ₆₃Eu. Firstly, the probability of creation of a single hole K state has been calculated. Double hole state L₁M_x is created by Coster-Kronig transitions (K − L₁M_x) as well as by shake off process. The probabilities of these two processes have been calculated. The total probability of creation of the double hole state thus obtained has been statistically distributed among the 24 allowed transitions from the set of L₁M_x levels. By taking each of the transitions as a Gaussian line, a composite spectrum has been computed. This theoretical spectrum has been compared with the available satellite energy data. The transitions which give rise to this satellite have thus been identified in the elements studied.

[en] The process, when electron is not emitted from the nucleus, but is transferred on one of the upper shells due to the resonance, is named the Auger effect. The calculation of the probability of the L₁L_IIIM_V transition with the M_V-electron throw up onto the np_3/2 levels (n - the main quantum number) for the Z = 50, 51, 73, 74 elements is accomplished in this work. It turned out that the probability of such a transition is lesser than the probability of the regular Coster-Kronig L₁-L_IIIM_V transition

[en] The effect on low-energy atomic inner-shell Coster-Kronig and super Coster-Kronig transitions that is produced by relaxation and by exchange between the continuum electron and bound electrons was examined and illustrated by specific calculations for transitions that deexcite the 3p vacancy state of Zn. Taking exchange and relaxation into account is found to reduce, but not to eliminate, the discrepancies between theoretical rates and measurements

[en] The 3p-hole lifetime widths of atomic and metallic Zn are calculated by an ab-initio atomic many-body theory. The frozen-core extended random-phase approximation with exchange (RPAE) using the atomic (super) Coster-Kronig (CK)-electron kinetic energy predicts well the atomic widths, whereas the same approximation using the metallic (s)CK-electron kinetic energy overestimates the metallic lifetime widths. The use of the orbitals relaxed in an ionic state together with the extended RPAE and metallic (s)CK-electron kinetic energy can predict well the metallic lifetime widths. The atomic and metallic lifetime widths are analyzed in detail. Why an ab-initio atomic many-body theory often works so well for metallic (solid-state) spectra is discussed in light of the change in the initial core-hole self-energy from free atom to metal

[en] Two theoretical methods, namely perturbation theory of Z-expansion (MZ code) and multi-configurational Hartree-Fock methods (Cowan code), were used for identification of Coster-Kronig (CK) electron spectra from the singlet and triplet 1s²2p9l states of S¹²⁺. The correlation effects are discussed through comparison between two methods. Transition energies have also been calculated for CK electron energy from 1s²2pnl (n=10-20) states. (orig.)

[en] Highlights: • High resolution L₁-L_2,3M Coster-Kronig spectra in Ar are obtained by electron impact. • Many features are due to the autoionizing decay of neutral doubly excited states. • Energy analysis of ejected electrons ruled out hypothesis of the state origins. - Abstract: The ejected electron spectra between 25 and 56 eV kinetic energy in Ar have been measured at several electron impact energies. When the incident energy is above the Ar 2s ionization potential the peaks due to the L₁-L_2,3M₁ and L₁-L_2,3M_2,3 Coster-Kronig (CK) transitions are expected to occur in this region of kinetic energy, but we observe a series of other narrow structures that overlap and sometime dominate the spectrum due to the CK transitions. These features have been attributed to the autoionizing decay of inner valence doubly excited states to the Ar ⁺ ground state.

[en] The alignment parameters for L₃-subshells of Cd and Sb atoms are obtained by measuring the degree of polarization of the L₁-lines excited by proton impact in the range from 0.1 to 0.5 MeV. The semiempirical value of the corrections for alignment parameters have been derived from measured L-line intensities with account of Coster-Kronig transitions

[en] The number of studies in M-shell ionization is considerably low compared to the other two shells i.e., K and L shell. Apart from direct coulomb ionization, simultaneous multiple ionization in higher shells and electron capture in the K and L shell of the projectile from target M shell may be significant in case of M-shell ionization. Here we have considered the initial electron capture cross-section formulation of K-shell electron capture from Nikolaev and Lapicki approach (Nikolaev, 1967), (Lapicki et. al., 1980) and extended (modified) for target M-shell. The simultaneous multiple ionisations (SMI) have been considered in the theoretical X-ray production cross-section by modifying the fluorescence yield and Coster-Kronig transition rates by SMI probability for higher shells using Binary-Encounter Approximation. The probability of electron capture becomes a dominating factor if the active target electron binding energy is comparable to the binding energy of the projectile shell where the electron is being captured. However, to obtain the actual capture cross-section contribution in the total ionization phenomena we need to consider the charge state of the projectile inside the target atom. Irrespective of moving with an initial charge state, the projectile acquires a charge state distribution inside the target material and each charge state has a different contribution fraction in cross-section. The distribution has been taken to be the Lorentz distribution about a mean charge state obtained from several empirical models depending on the energy of the projectile. (author)

[en] The L X-rays intensity ratio and L subshell fluorescence yield ratios has been measured by several investigators using gamma radiation, X-ray and charged particles. The good agreement between experimental and theoretical values indicates that present techniques can be adopted for measurement of L2 X-rays intensity ratio as well as L subshell fluorescence yield ratio for other targets as well as compounds in order to investigate the role of Coster-Kronig transition in this process