Original scientific paper
The line shape of sodium n2S1/2-32P1/2;3/2 transitions in Na-Cd high pressure discharge
Željka Mioković
; Electrotechnical faculty, K. Trpimira 2b, 31000 Osijek, Croatia
Damir Veža
; Department of Physics, P.O.B. 331, Bijenička 32, HR-10002 Zagreb, Croatia
Abstract
We measured sodium atomic lines belonging to the n2S1/2-32P1/2;3/2 (n = 5,6,7) series, originating from a high-pressure sodium-cadmium plasma. The observed line shapes are compared with the calculations of the line shapes made within the Bartels' method. The electron density is estimated by Vidal approach (a refined Inglis-Teller method), and the density of sodium and cadmium has been determined using the relationships between the interaction constants of the sodium-sodium (sodium-cadmium) quasimolecule and the shift of the self-absorbed peaks of the sodium resonance line. We assume that the main line-broadening mechanisms of n2S1/2-32P1/2;3/2 spectral lines are Stark broadening (by electrons), self-broadening (by neutral sodium atoms) and van der Waals broadening (by cadmium atoms). The electron temperatures are determined by Bartels' method, fitting the calculated to the experimentally measured n2S1/2-32P1/2;3/2 line profiles. All three measured lines possess a red asymmetry that can not be attributed to the electron broadening, self-broadening or foreign gas broadening. We suggest that this red asymmetry could be caused by interaction of the radiating sodium atom with sodium and cadmium ions.
Keywords
high-pressure Na-Cd plasma; atomic lines; n2S1/2-32P1/2; 3/2 (n = 5; 6; 7) series; line shapes; Stark broadening by electrons; self-broadening; van der Waals broadening; red asymmetry
Hrčak ID:
301106
URI
Publication date:
1.8.2001.
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