XXXVI international conference on plasma physics and CF, February 9 – 13, 2009, Zvenigorod.
THEORETICAL STUDY OF THE ARGON SPECTRUM IN AN ALTERNATING
ELECTRIC FIELD FOR TRANSITIONS WITH J1
Koryukina E.V.
Tomsk state university, Tomsk, Russia, evk@phys.tsu.ru
An electric field in a gas discharge and transition probabilities are ones of the most important
characteristics of the discharge. These characteristics are used for theoretical investigation of
processes taking place in plasma and for plasma diagnostics also. Of special interest is a study of
emission spectra of rare gases, in particular, the argon spectrum because this gas is widely used in
plasma physics. An actual problem is theoretical investigation of the emission spectrum of the
argon in a circular polarized alternating electric field which is realized in a high-frequency
discharge and under laser excitation.
A general analysis of calculations performed in this work in the framework of a theoretical
approach suggested in [1] allows us to reveal the number of regularities for the emission spectrum
of the argon in above mentioned electric fields. It was shown, that spectral lines corresponding to
the n1l1΄[K1]J1M1→n2l2΄[K2]J2M2 and n1l1[K1]J1M1→n2l2[K2]J2M2 transitions demonstrate
completely different behavior at the changes in both strength and frequency of external electric
field. An increase in the electric field strength leads to usual shift and splitting of spectral lines
corresponding to the n1l1΄[K1]J1M1→n2l2΄[K2]J2M2 transitions. Line shifts are proportional to F2, the
splitting of levels decreases with the growth of the electric field frequency. Meanwhile, an increase
in the strength and frequency of the electric field leads to anomalies of shifts and splitting of
spectral lines corresponding to the n1l1[K1]J1M1→n2l2[K2]J2M2 transitions. The reason for the
dissimilarity of the behavior of these two types of lines is the difference in a degree of mixture of
energy levels in the electric field.
The same reason is at the basis of the difference in the behavior of the transition probabilities at
the changes in the frequency and strength of the electric field. Probabilities of the n1l1΄[K1]J1M1→
n2l2΄[K2]J2M2 transitions are practically independent of the changes in the frequency and strength of
the electric field and equiprobable for the M→±M΄ transitions, while probabilities of the
n1l1[K1]J1M1→n2l2[K2]J2M2 transitions can both decrease and increase with the strength and
frequency of the electric field. Strong interaction of energy levels leads to an anisotropy of
probabilities of the n1l1[K1]J1M1→n2l2[K2]J2M2 transitions. Finally, a polynomial dependence of
probabilities of the J→J΄ transitions on the electric field strength was revealed, and it was found that
a degree of the polynomial increases with the electric field frequency.
Theoretical results obtained in the present work can be used for an explanation of physical
processes taking place in plasma generated by the circular polarized alternating electric field. In
particular, based on calculated data, it is possible to determine the electric field strength inside the
discharge, clarify the mechanisms of filling of excited levels and reasons for the changes of spectral
line intensities. Moreover, obtained regularities also can be useful at modeling of new light sources
and excitation sources.
References
[1]. Koryukina E.V., J.Phys.D: Appl.Phys, 2005, 38, 3296-3303
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