From: "Louis St-Onge" <louis.st-onge@nrc.ca>
Newsgroups: sci.physics.plasma
Subject: Re: Fine Structure in emission spectra
Organization: National Research Council of Canada
References: <8521c0$j8p$1@jupiter.cs.uml.edu>


The fine structure appears because of the existence of the electronic spin,
a strictly quantum-mechanical quantity. Because of coupling between orbital
momentum of the electron and its spin, different atomic states become
possible (with different energies) corresponding to different possible
"combinations" of orbital motion and spin orientations. Suggested reading:
G. Herzberg, Atomic spectra and atomic structure.

L.S.

"Mr J C Bowden" <SaschaH@bigpond.com> wrote in message
news:8521c0$j8p$1@jupiter.cs.uml.edu...
> Hello,
>
> I would like an explanation of the existence of the what I will call "fine
> structure" in energy levels of argon, as seen in argons emission spectra.
> Publications such as "On excitation temperature measurements in a
> plasma-jet, and transition probabilities for argon lines" (B.D. Adcock and
> W. E. G. Plumtree, J. Quant. Spectrosc. Radiat. Transfer, vol4 pp29-39
1964)
> show multiple levels (separated by approx.. 400cm-1) for each orbital
> present (i.e. 4p, 5p, 5d etc.) these sub-level fine structure elements are
> numbered from 1 to 10 for the p levels.
> These levels can not be rotational or vibrational levels, and beyond that
I
> have not a clue to what they are.
>
> Any hint/jolt of memory to what they are caused by would be appreciated.
>
> Thanks
>
> Josh Bowden
>
>
>