P. Bogdanovich, R. Kisielius, and D. Stonys
Received 20 December 2013; revised 13 March 2014; accepted 29 May
2014
We describe the computer codes,
developed at Vilnius University, for the calculation of
electron-impact excitation cross sections, collision strengths,
and excitation rates in the plane-wave Born approximation. These
codes utilize the multireference atomic wavefunctions which are
also adopted to calculate radiative transition parameters of
complex many-electron ions. This leads to consistent data sets
suitable in plasma modelling codes. Two versions of electron
scattering codes are considered in the present work, both of
them employing configuration interaction method for inclusion of
correlation effects and Breit-Pauli approximation to account for
relativistic effects. These versions difer only by one-electron
radial orbitals, where the first one employs the nonrelativistic
numerical radial orbitals, while the other version uses the
quasirelativistic radial orbitals. The accuracy of produced
results is assessed by comparing radiative transition and
electron-impact excitation data for neutral hydrogen, helium,
and lithium atoms as well as highly charged tungsten ions with
theoretical and experimental data available from other sources.
Keywords: electron impact, excitation, many-electron
ions
PACS: 31.15.ag,
34.80.Dp, 95.30.Ky
Aprašome Vilniaus universiteto
Teorinės fizikos ir astronomijos instituto Atomo teorijos
skyriuje sukurtas kompiuterines programas, skirtas skaičiuoti
atomų ir jonų sužadinimo elektronų smūgiais skerspjūvius, smūgių
stiprius ir sužadinimo greičius plokščiųjų bangų pirmajame Borno
artinyje. Šios programos naudoja daugiakonfigūracines
daugiatermes atomo bangines funkcijas; tos pačios banginės
funkcijos yra pritaikomos sudėtingų daugiaelektronių jonų
radiacinių šuolių parametrams (šuolių bangų ilgiams, šuolių
osciliatorių stipriams, šuolių tikimybėms) skaičiuoti. Tokiu
būdu įmanoma gauti patikimus duomenis, tinkamus plazmų
modeliavimo programoms.
Šiame darbe tiriame dvi skirtingas elektronų sklaidos programas,
tačiau jos abi naudoja konfigūracijų sąveikos metodą
koreliaciniams efektams įskaityti bei Breito ir Paulio artinį,
leidžiantį įvertinti reliatyvistinius efektus. Šios dvi
programos skiriasi tik vienelektronėmis radialiosiomis
orbitalėmis; pirmoji programa naudoja nereliatyvistines
skaitines radialiąsias orbitales, o antroji –
kvazireliatyvistines radialiąsias orbitales. Mūsų duomenų
tikslumą įvertiname palygindami juos su kitų autorių neutralių
vandenilio, helio ir ličio atomų bei daugiakrūvių volframo jonų
radiacinių šuolių ir sužadinimo elektronų smūgiais teoriniais
rezultatais bei eksperimentiniais duomenimis.
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