A Slater parameter optimization method applied to the computation of collision strengths for Fe XIII

Journal Article · Wed Nov 01 00:00:00 EST 1989 · Atomic Data and Nuclear Data Tables; (USA)

DOI:https://doi.org/10.1016/0092-640X(89)90002-8· OSTI ID:5837487

Fawcett, B C ^[1]; Mason, H E ^[2]

---

1. Rutherford Appleton Laboratory, Oxfordshire (England)
2. Department of Applied Mathematics and Theoretical Physics, Cambridge (England)

Details of a new computational method for calculating collision strengths are presented through an application to Fe XIII. The method, which enables the computation of collision strengths for complex ions, is adapted from long-established optimization techniques previously used for the calculation of atomic energy levels and oscillator strengths. The procedure involves the adjustment of Slater parameters and average energies of configurations so that they result in improved energy levels and eigenvectors. These improved values can then provide a basis for collision strength calculations in ions where ab initio computations break down or result in unnecessarily large errors. The present application is implemented through modifications of the DISTORTED WAVE collision code and SUPERSTRUCTURE atomic-structure code interfaced via a transformation code JAJOM, which also processes their output; these atomic codes were written at University College London. It should be feasible to make similar adaptations to other collision codes. The Cowan suite of atomic-structure codes generated the optimized parameters. Fe XIII collision strengths are tabulated for 3s{sup 2}3p{sup 2}-3s3p{sup 3} and 3s{sup 2}3p{sup 2}-3s{sup 2}3p3d transitions. Six configurations, 3s{sup 2}3p{sup 2}, 3p{sup 4}, 3s{sup 2}3p3d, 3s3p3d{sup 2}, and 3p{sup 3}3d, were included in these computations.

• OSTI ID: 5837487
• Journal Information: Atomic Data and Nuclear Data Tables; (USA), Vol. 43:2; ISSN 0092-640X
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ELECTRON-ION COLLISIONS
EXCITATION
IRON IONS
CALCULATION METHODS
D CODES
EIGENVECTORS
ELECTRONIC STRUCTURE
ENERGY LEVELS
ENERGY-LEVEL TRANSITIONS
J CODES
MULTICHARGED IONS
OPTIMIZATION
OSCILLATOR STRENGTHS
S CODES
SLATER METHOD
STRENGTH FUNCTIONS
CHARGED PARTICLES
COLLISIONS
COMPUTER CODES
ELECTRON COLLISIONS
FUNCTIONS
ION COLLISIONS
IONS
640304* - Atomic
Molecular & Chemical Physics- Collision Phenomena