Questions on the Lyman Alpha Profile

[neilparker62]

What do you mean by 'Lyman Beta (H) and Lyman Beta (D)' These two peaks here a caused by self-reversal/abosrption of the line in the solar atmosphere (geocoronal absorption can be neglected for Lyman Beta). The frequency/wavlength shift for deuterium is only about 0.03pm ( http://en.wikipedia.org/wiki/Deuterium ) so completely negligible here. Also, the abundance of deuterium is only of the order of 10^-4 of that of hydrogen, so it practically not contribute to the measured intensity anyway.( http://adsabs.harvard.edu/full/1962Obs...82..106R )

I mean wavelength of Lyman Beta for Hydrogen and wavelength of Lyman Beta for Deuterium. The shift for Lyman Alpha is about 33 pico meters (- c Δf / f^2 with Δf and f from Parthey's measurements) and for Lyman Beta 27.9 pico meters. And I measured the peak to peak difference on Artzner's Lyman Alpha profile and it was about 33 pico meters. And I measured the peak to peak difference on a Lyman Beta profile from the source I mentioned and it was about 28 pico meters. That is the co-incidence I refer to and I have elsewhere in this post attempted to address the question of relative abundance of Hydrogen vs Deuterium.

 

[Fantasist]

Yes, sorry, I got the frequency shift wrong. I think the figure I found may have been given in kHz and I didn't apply the factor 1000 for this (I can't find the reference anymore).
Anyway, if there were about equal amounts of hydrogen and deuterium in the sun's atmosphere the combined line would look different: you would have the same feature superimposed again shifted 33 pm to the blue, so there would be a very obvious asymmetry with regard to the central geocoronal absorption line. The Artzner paper speaks of a slight asymmetry, but this is exactly in the other direction, i.e.effectively a red-shift.

 

[neilparker62]

The central absorption line in the profile is geo-coronal and would thus definitely reflect the very strong predominance of hydrogen that you refer to. I am not suggesting equal amounts of hydrogen and deuterium in the sun's atmosphere either since - from what I understand - deuterium is further 'processed' to form helium and other elements. What I am suggesting is that if we are looking at the spectral signature of energy production via nuclear fusion in the sun then there would be a certain population of hydrogen with enough energy to undergo fusion forming an approximately similar population of equally high energy deuterium. These 'high energy' populations of hydrogen and deuterium would then quickly dissipate energy releasing radiation in all allowed parts of the spectrum. At some point there would be a separation (perhaps by mass) leading to further fusion of deuterium and hence the established low ratio thereof. The problem with this theory is that the peaks are in the wrong place - they are massively red-shifted with respect to the known wavelengths of Lyman Alpha H and D. But who knows what sort of dynamics would be present in terms of solar downflows etc immediately following fusion reactions?

 

[Fantasist]

The central absorption line in the profile is geo-coronal

It is actually a combination of geocoronal and solar absorption. You can see the solar self-reversal directly in case of the Lyman-beta line (where there is no significant georonal absorption as the absorption cross section for Lyman-Beta is considerably smaller than for Lyman-Alpha, so the opacity is smaller). The Lyman-Alpha line has a similar solar absorption, but here the (much narrower) geocoronal absorption line is added.

The problem with this theory is that the peaks are in the wrong place - they are massively red-shifted with respect to the known wavelengths of Lyman Alpha H and D. But who knows what sort of dynamics would be present in terms of solar downflows etc immediately following fusion reactions?

The 'peaks' that you see here are not related to any characteristic physical frequencies. They are the result of the 'self-reversal' of the emission line that will inevitably occur if the medium has a large (>>1) opacity. Since the opacity is highest in the center of the line (because there are more atoms there according to the Maxwell velocity distribution) photons are scattered more often there and can not escape as easily from the medium. During the cause of the scattering they experience a frequency shift due to the Doppler effect away from the line center where they can escape more easily (as the opacity is smaller there). This lead to the development of the 'twin peaks' (which thus consists of photons that were emitted originally in or near the line center). The higher the opacity of the medium, the more the peaks will shift away from the center.

If you would manage to detect he spectral signature of deuterium it would look more like shown in this paper http://arxiv.org/pdf/astro-ph/0002141v1.pdf