Gold & band structure at grazing angle

AI Thread Summary
The discussion focuses on the refraction index of gold at grazing angles, particularly in X-ray applications. It explains that X-ray photon energies exceed the binding energies of atomic electrons, resulting in a refractive index less than one, which allows for total external reflection at a critical angle. This phenomenon is essential for X-ray telescopes, which utilize parallel mirrors to reflect high-energy rays effectively. Participants share resources, including a paper and a website with images of mirror geometries, to aid in understanding the topic. The conversation concludes with a request for data on the band structure of materials used in these applications.
skyboarder2
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Hi everybody,

I would like to know if someone could explain to me what happens to the refraction index of gold at grazing angle (X-ray applications), and particularly the band structure explanation (if you have it!)...
Indeed, I heard that the x-ray telescopes were made of parallel mirrors for the material to absorb the rays at grazing angle, the only way for them to REFLECT these high-energy rays.
Thank you very much,
S2
 
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"X-ray photon energies are greater than the binding energies of the typical atomic electrons leading to an index of refraction, n < 1 except near absorption edges of the material used. Then by Snell’s Laws, total external reflection occurs and X-rays reflect from a surface up to a critical angle given by cosine θ = n. This is known as the grazing angle."
This quoted from http://www.ias.ac.in/resonance/June2005/pdf/June2005p15-23.pdf.

Also http://www.x-ray-optics.com/index.php?option=com_content&view=article&id=59&Itemid=71&lang=en#Wolter_optics has some nice pictures of the mirror geometry used.
 
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Wow, that's precious! Thank you very much, how did you find these sources?
I just need to find some data about the band structure of the materials used and I'll have all I want, could you tell me by what means you got these websites/pages? Thank you so much
 
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