Excitation-autoionization through 3[ital d]-4[ital l] inner-shell excitations in Cu- to Kr-like ions and the effect on fractional-ion-abundance balance in coronal plasmas

Journal Article · Thu Dec 01 04:00:00 EST 1994 · Physical Review A; (United States)

DOI:https://doi.org/10.1103/PhysRevA.50.4911· OSTI ID:6938959

Mitnik, D; Mandelbaum, P; Schwob, J L ^[1]; Bar-Shalom, A; Oreg, J ^[2]; Goldstein, W H ^[3]

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1. Racah Institute of Physics, The Hebrew University, 91904 Jerusalem (Israel)
2. Nuclear Research Center-Negev, P.O. Box 9001, 84190 Beer Sheva (Israel)
3. Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550 (United States)

Excitation of inner-shell electrons into autoionizing levels followed by autoionization (EA) can enhance the total ionization rate. For ions isoelectronic to elements of the fourth row, the present results show that the enhancements can be much more important than those previously calculated for the preceding isoelectronic sequences. [Delta][ital n]=1 3[ital d]-4[ital l] inner-shell excitations, which are the dominant EA channels, are considered here. Detailed computations of EA rates were performed using the relativistic distorted-wave method, and the behavior of the EA rate coefficients along the Cu, Zn, Ga, and Kr isoelectronic sequences has been analyzed. In the other sequences from Ge to Br with configurations involving a very large number of levels, EA calculations have been performed for a few elements only. In view of an easy use of the data, and for application to other elements, approximate analytical expressions have been deduced for ionization energies, average inner-shell excited-configuration energies, total electron-impact excitation rates, as well as average branching ratios for autoionization. These data enable a direct evaluation of the EA rates in all the sequences from Cu to Kr for all the elements with 40[le][ital Z][le]92. Finally, the EA rate coefficients were introduced in the coronal ionization rate equations. Fractional ion abundances for Mo ([ital Z]=42), Xe ([ital Z]=54), Pr ([ital Z]=59), and Dy ([ital Z]=66) obtained with and without taking into account EA processes are presented. The results show a decrease of up to 40% in the temperature of maximum abundance for Kr- to Ni-like ions.

• OSTI ID: 6938959
• Journal Information: Physical Review A; (United States), Journal Name: Physical Review A; (United States) Vol. 50:6; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

664300* -- Atomic & Molecular Physics-- Collision Phenomena-- (1992-)
74 ATOMIC AND MOLECULAR PHYSICS
ATOM COLLISIONS
ATOMS
AUGMENTATION
AUTOIONIZATION
CALCULATION METHODS
CHARGED PARTICLES
COLLISIONS
COPPER
DISTORTED WAVE THEORY
ELECTRON COLLISIONS
ELECTRON-ATOM COLLISIONS
ELEMENTS
ENERGY RANGE
ENERGY-LEVEL TRANSITIONS
EXCITATION
FLUIDS
GALLIUM
GASES
HEAVY IONS
INNER-SHELL EXCITATION
IONIZATION
IONS
ISOELECTRONIC ATOMS
KRYPTON
METALS
NONMETALS
PLASMA
RARE GASES
RELATIVISTIC RANGE
TRANSITION ELEMENTS
ZINC