From: "Mr J C Bowden" <SaschaH@bigpond.com>
Newsgroups: sci.physics.plasma
Subject: Fine Structure in emission spectra
Organization: Telstra BigPond Internet Services (http://www.bigpond.com)

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