Stark shifts and transition probabilities in Si III and Si IV spectra

¹ Faculty of Physics, University of Belgrade 11001 Belgrade, PO Box 368, Serbia, Yugoslavia
² Isaac Newton Institute of Chile, Yugoslavia Branch, Belgrade, Yugoslavia
³ Hungarian Academy of Sciences, Budapest, Hungary
⁴ Astronomical Observatory, 11160 Belgrade, Volgina 7, Serbia, Yugoslavia

Corresponding author: S. Djeniže, srdjan_bukvic@Softhome.net

Received: 24 May 2002
Accepted: 10 September 2002

Abstract

Stark shifts of nine doubly charged (Si III) and six triply charged (Si IV) silicon ion spectral lines have been measured in a linear, low-pressure, pulsed arc operated in O₂ and SF₆ discharges. Si III Stark shift values have been also calculated using the semiclassical perturbation formalism (SCPF) for electrons, protons and helium ions as perturbers. Transition probabilities of the spontaneous emission (Einstein's A values) of nine Si III transitions have been obtained using the relative line intensity ratio (RLIR) method, not applied before in Si III spectrum, and, also, calculated using the Coulomb approximation method. The measured Si IV shift and some calculated Si III shift values present the first published data in this field.