Talk:Atomic spectral line

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Help with this template Comments: edit – history – watch – refresh The idea of an atomic spectral line is of "top" importance for physics. The explanation of these was THE big prediction of early quantum mechanics and motivated developments in all other areas of physics. I think this article is just a "start" though. It has some discussion of Einstein coefficients and such, but perhaps material that is more related to atomic physics would be useful too -- eg, explain the Balmer or Lyman series, mention the idea of jumping between energy levels defined by the Schrodinger equation, etc, to get a wider viewpoint. Also some introduction for the non-scientifically-literate user in the beginning would be nice too. Wesino 00:51, 29 November 2006 (UTC)

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A new spectral line intensity formula for optical emission spectroscopy was presented by Dr:s Bo Thelin (experimental physicist) and Sten Yngström (theoretical physicist) at the beginning of the 1980:s. This formula has shown very good agreement between experiments (Ref 1) and the new theory (Ref 2). These references are summaries of earlier papers.

I = K \ left (frac { v^2 }{ c^2 }\ right ) \ e^left (\ frac { -J}{ k \ T \ right )} \ \ left (\ e^left ( \ frac { h \ v }{ k \ T \right - \ 1)^-1

K includes transition rates and element concentrations I= spectral line intensity, V= frequency , J=ionization energy and T=temperature

Many independent experimental methods strongly support the new formula, while the standard intensity formula with the Boltzmann term (upper energy level), deviates very much from experiments. Ref 1 Yngström,S. and Thelin,B. Applied Spectroscopy, 44, 1566, (1990) Ref 2 Yngström,S. International Journal of Theoretical Physics,Vol.33, No 7,(1994)--79.138.179.27 (talk) 21:34, 10 March 2008 (UTC)

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1. In section oscillator strength: is undefined.

2. Comparing the formular connecting and with the expression in the book of Bransden&Joachain "Physics of atoms and molecules", one get's the impression that CGS-units are used here, where the permeability of vacuum, , is . Maybe SI units are more appropriate here on wikipedia.

3. Comparing the expressions for and to Bransden&Joachain, would be , inconsistent with point(2.). It seems like the "c" in the denominators should not appear there.

Contents 1 Question 2 stimulated emission image 3 B12, is it function of ν ? 4 rewritten introduction 5 What is A12? 6 In terms of oscillator strengths

[edit] Question

These questions were moved from the article. PAR 14:59, 22 June 2006 (UTC)

Question: The Wikipedia article on Einstein refers to his publishing the concept of spontaneous emission in Physikalische Zeitschrift in 1917, not 1916. Is there documentary evidence for the 1916 date?

Also, Bertolotti's book on the history of masers and lasers says that Einstein did not actually use the term "stimulated emission", which was only introduced later by Van Vleck. Comments on this?

[edit] stimulated emission image

I believe that the created photon in the stimulated emission image should be moving in the same direction as the catalyst photon.

Good idea - I have changed it. PAR 02:21, 5 October 2006 (UTC)

[edit] B₁₂, is it function of ν ?

and : shouldn't they be replaced to , ?

[edit] rewritten introduction

A few points

• Yes, the distinction between emission and absorption lines should be noted in the beginning.
• absorption is not the same as the photoelectric effect. In the photoelectric effect the electron is ejected from the material, not pushed to a higher energy level.
• Continuum radiation is well defined. Continuum radiation comes about when the distribution of photon energies is continuous over a relatively large interval. The spectrum itself may not be continuous in the usual sense, but the probability distribution for photon energies is.
• Spectral lines only occur in bound-bound transitions. Bound-bound transitions are crucial to the understanding of atomic lines and should not be stuck at the end of the article under a "terminology" section. Bound-free transitions form a continuum, not a spectral line.

PAR 14:24, 27 October 2006 (UTC)

[edit] What is A12?

"When this relation is inserted into the original equation, one can also find a relation between A12 and B12, involving Planck's law."

[edit] In terms of oscillator strengths

At the bottom of the article, the coefficients are expressed in terms of the oscillator strength f₁₂. The formulas there cannot all be correct: when one makes the divisions, not the same expressions (e.g. for ) are found as those stated above. E.g., both have a factor π² which disappears when the division is done, and also the speed of light c is present as c in one and as c³ in the other; the division would lead to c², not c³. —Preceding unsigned comment added by 131.155.108.140 (talk) 10:25, 8 January 2008 (UTC)

--- What is ? dima 13:01, 21 December 2006 (UTC)