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A: Atomphysik

A 12: Posters Thursday (Ion/Atom/Molecule/Surface Scattering)

A 12.48: Poster

Donnerstag, 5. April 2001, 12:30–15:00, AT3

Heavy particle collision induced inelastic cross-sections for fine structure level transitions in hydrogen-like ions — •Stanislav Alekseev — School of EEIE, South Bank University, 103 Borough Road, London SE1 0AA, U.K.

S.N. Alekseev and N.N. Ljepojevic Centre for Computer and Mathematical Modelling, School of EEIE, South Bank University, London, U.K.

Abstract: Proton and other heavy charged particle induced transitions between the fine-structure levels with the same principal quantum number n in hydrogen-like ions are of principal importance when the fine structure line ratios are considered [1]. Originally, the cross-sections for optically allowed transitions were calculated using a two-state impact parameter method in the dipole approximation [2, 3, 4]. In the present work many-state impact parameter calculations with full transition matrix elements are developed. The principal shells with n = 2, 3 and 4 are considered. The convergence of the results as more states are added is studied. Also, the high-energy behaviour of cross-sections is examined, and it is found that the 1/E law holds true for the optically allowed transitions. The results are compared with the two-state calculations.

[1] N.N. Ljepojevic, R.J. Hutcheon and R.W.P. McWhirter, J. Phys. B: At. Mol. Phys. 17 (1984) 3057 [2] N.N. Ljepojevic, R.J. Hutcheon and J. Payne, Comput. Phys. Commun. 44 (1987) 157 [3] A. Burgess and H. Summers, Mon. Not. R. Astr. Soc. 174 (1976) 345 [4] V.P. Shevelko, Yu.I. Skobelev and A.V. Vinogradov, Phys. Scripta 16 (1977) 123