A Complete Set of Radiative and Auger Rates for K-vacancy States in Fe XVIII-Fe XXV

A complete set of level energies, wavelengths, A-values, and total and partial Auger rates have been computed for transitions involving the K-vacancy states within the n= 2 complex of Fe xviii-Fe xxv. Three dierent standard numerical packages are used for this purpose, namely autostructure, the Breit-Pauli R-matrix suite (bprm )a ndhfr, which allow reliable estimates of the physical eects involved and of the accuracy of the resulting data sets. The Breit interaction is taken into account because its contributions to the small A-values and partial Auger rates cannot be neglected with increasing electron occupancy. Semiempirical adjustments can also lead to large dierences in both the radiative and Auger decay data of strongly mixed levels. Several experimental level energies and wavelengths are questioned, and significant discrepancies are found with previously computed decay rates that are attributed to numerical problems. The statistical accuracy of the present level energies and wavelengths is ranked at 3e V and2 mA, respectively, and that for A-values and partial Auger rates greater than 10 13 s 1 at better than 20%.

[1]  W. D. Robb,et al.  A new version of the general program to calculate atomic continuum processes using the r-matrix method , 1984 .

[2]  W. D. Robb,et al.  Electron scattering by complex atoms , 1971 .

[3]  Nigel R. Badnell,et al.  On the effects of the two-body non-fine-structure operators of the Breit - Pauli Hamiltonian , 1997 .

[4]  H. Nussbaumer,et al.  A programme for calculating atomic structures , 1969 .

[5]  N. Badnell.  Dielectronic recombination of Fe22+ and Fe21+ , 1986 .

[6]  M. Chen,et al.  K-SHELL AUGER AND RADIATIVE TRANSITIONS IN THE CARBON ISOELECTRONIC SEQUENCE, 6 ≤Z≤ 54 , 1997 .

[7]  R. D. Cowan,et al.  The Theory of Atomic Structure and Spectra , 1981 .

[8]  U. Safronova,et al.  Inner-shell excitation energy and autoionization rates for Li-, Be-, B-like ions with Z = 6–54 , 1996 .

[9]  Mau H. Chen,et al.  Dielectric satellite spectra of Li-like ions , 1987 .

[10]  É. Biémont,et al.  IONIZATION POTENTIALS OF ATOMS AND IONS FROM LITHIUM TO TIN (Z= 50)☆☆☆ , 1999 .

[11]  K. Berrington,et al.  The QB program: Analysing resonances using R-matrix theory , 1998 .

[12]  U. Feldman,et al.  Measurement of wavelengths and lamb shifts for inner-shell transitions in Fe XVIII-XXIV , 1986 .

[13]  Mau H. Chen,et al.  Dielectronic satellite spectra for He-like ions , 1986 .

[14]  U. Safronova,et al.  Inner-shell Excitation Energies and Autoionization Rates for C-, N-, O-, and F-like Ions with Z = 6–54 , 1999 .

[15]  J. Dubau,et al.  Electron Excitation Cross-Sections and Oscillator Strengths for Highly Ionised Atoms , 1981 .

[16]  Drake.  Spontaneous two-photon decay rates in hydrogenlike and heliumlike ions. , 1986, Physical review. A, General physics.

[17]  U. Feldman,et al.  High-resolution X-ray spectra of the 1979 March 25 solar flare , 1980 .

[18]  Verne L. Jacobs,et al.  High-Resolution Measurement of the Kα Spectrum of Fe XXV-XVIII: New Spectral Diagnostics of Nonequilibrium Astrophysical Plasmas , 1997 .

[19]  J. Nilsen,et al.  COMPARISON OF SATELLITE SPECTRA FOR H-LIKE Fe AND He-LIKE Fe, Ca, AND S CALCULATED BY THREE DIFFERENT METHODS , 1997 .

[20]  J. Dubau,et al.  Autoionization rates for 1s2s22p2, 1s2s2p3, 1s2p4 states of B-like ions (6 < Z < 54) for decay via different channels , 1998 .

[21]  T. Phillips,et al.  High-resolution measurements, line identification, and spectral modeling of K-alpha transitions in Fe XVIII-Fe XXV , 1993 .

[22]  C. Mendoza,et al.  Atomic data from the IRON Project , 1998 .

[23]  C. Mendoza,et al.  Atomic data from the IRON Project - XXII. Radiative rates for forbidden transitions within the ground configuration of ions in the carbon and oxygen isoelectronic sequences , 1997 .

[24]  W. D. Robb,et al.  A general program to calculate atomic continuum processes using the R-matrix method , 1984 .

[25]  W. Eissner,et al.  Techniques for the calculation of atomic structures and radiative data including relativistic corrections , 1974 .

[26]  U. Safronova,et al.  Perturbation theory Z expansion for many-electron autoionisation states of atomic system. II. Autoionisation rates and radiative transition probabilities , 1980 .

[27]  Norman Scott,et al.  A general program to calculate atomic continuum processes incorporating model potentials and the Breit-Pauli Hamiltonian within the R-matrix method , 1984 .

[28]  Jacobs,et al.  Effects of initial-state population variations on the 2p-->1s K alpha dielectronic satellite spectra of highly ionized iron ions in high-temperature astrophysical and laboratory plasmas. , 1989, Physical review. A, General physics.

[29]  P. Burke,et al.  Electron scattering by atoms and ions using the Breit-Pauli Hamiltonian: An R-matrix approach , 1980 .

[30]  K. Berrington,et al.  The QB method: analysing resonances using R-matrix theory. Applications to , He and Li , 1996 .