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FIZIKA A 10 (2001) 3 , 129-140
 
THE LINE SHAPE OF SODIUM n2S1/2-32P1/2;3/2
TRANSITIONS IN Na-Cd HIGH PRESSURE DISCHARGE
ŽELJKA MIOKOVIĆa and DAMIR VEŽAb
aElectrotechnical faculty, K. Trpimira 2b, 31000 Osijek,
Croatia
bDepartment of Physics, P.O.B. 331, Bijenička 32, HR-10002
Zagreb, Croatia
Tel.: +385-1-4605555 E-mail address: veza@phy.hr
Dedicated to Professor Kseno Ilakovac on the occasion of his 70th
birthday
Received 20 July 2001; revised manuscript received 11 December 2001
Accepted 26 November 2001 Online 30 December 2001
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.
PACS numbers: 32.70.-n, 52.25.Rv
UDC 537.525
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
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