FIZIKA A 17 (2008) 4 , 159-164

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LETTER TO THE EDITOR

ELECTRON IMPACT EXCITATION OF AUTOIONIZING LEVEL IN Na

S. N. TIWARYa, R. KUMAR and R. P. K. RAY
Department of Physics, BRA Bihar University, Muzaffarpur, Bihar, India
aE-mail address: sntiwaryin@yahoo.com

Received 31 January 2008;   Accepted 3 December 2008
Online 4 March 2009

Electron-impact integral cross sections for the excitation of the lowest lying autoionizing level generated by the inner-shell 1s2 2s2 2p6 3s 2Se 1s2 2s2 2p5 3s2 2P0 complex transition in sodium (Na) atomic system have been calculated. In the calculation, single-configuration Hartree-Fock (HF) wave functions for both initial and final states involved in the transition matrix element within the asymptotic Green function approximation (AGFA) proposed by Tiwary (1981) were employed. The calculation was done exactly in the same way as in the earlier work in the case of the lightest alkali-metal atom lithium (Tiwary (1985), Tiwary, Macek and Madison (1985)) and the heaviest alkali-metal atom caesium (Tiwary (1983)) in the bombarding energy range from the threshold to 1500 eV. For the first time, Tiwary (1983) predicted the resonance behaviour in near vicinity of the excitation threshold in Cs using AGFA. Feuerstein et al. (1998) performed the experiment and observed resonance behaviour in the neighbourhood of excitation threshold in Na. Comparison has been made with available relevant experimental observations and other theoretical predictions. Our present AGFA theoretical result is qualitatively in accord with the experimental results.

PACS numbers: 34.80.Dp, 32.80.Dz, 31.10.+z
UDC 539.183, 539.186, 535.352

Keywords: electron-impact excitation, integral cross section, lowest autoionizing level, asymptotic Green function approximation (AGFA)

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