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% Reflection vs Wavelength Chart. Any?

  1. Dec 15, 2005 #1
    Does anyone have a link to a chart or table that shows the % of light reflection from some solid as the wavelength is changed from RadioWave to X-ray?
  2. jcsd
  3. Dec 15, 2005 #2


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    See Rohsenow & Hartnett, Handbook of Heat Transfer, for IR to UV properties of a handful of materials.
  4. Dec 15, 2005 #3

    Claude Bile

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    Obtaining a graph with such a large bandwidth would be difficult to obtain for several reasons;

    - More than one source and detector would be needed. Calibrating different sources and detectors to acheive a single output is extremely difficult.
    - Lack of near-monochromatic sources in some regions of the spectrum, most notably the THz region.
    - Lack of tunable sources in some regions of the spectrum.
    - Covering such a large region of the spectrum would invariably reduce the resolution of the scan, most likely defeating the whole purpose of performing such a scan in the first place.

    What exactly do you need this information for? Perhaps there is an alternative way to obtain what you seek.

  5. Dec 16, 2005 #4
    I'm trying to determine if there is a correlation between wavelength and atomic radii by looking at the % of the photons reflected. As an experienced spectroscopist (XPS, AES, NMR, UV, IR, MS, ToF-SIMS...) with some indepth knowledge of how XPS and AES systems work (or don't work), I'm familiar with the various limitations you noted. As a first pass, I can live with the non-linear response of the detectors. The response ranges will serve as a rough guide to the uncertainties in those parts of the spectral range. Just as you noted, there is no one spectral method that will provide what I seek, but life is hard and so I'm happy to get what ever I can. If something pops out, then we can go in for refinement and extension if money is made available.

    Alternatives are always welcome. So, have I explained my interest sufficiently? Many thanks for any help.
  6. Dec 16, 2005 #5
    Thanks Bystander. Much appreciated.
  7. Dec 18, 2005 #6
  8. Jan 9, 2006 #7

    Claude Bile

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    Just a couple more questions (and sorry for the late reply, I have been on holidays :biggrin: ).

    So you are measuring reflectivity as a function of wavelength, and looking for any correlation with atomic radii of the substance? If so there is an important issue that needs to be addressed.

    Take Carbon for example are your substance of interest, Carbon has many forms, Diamond, Graphite, Buckyballs etc. All have different macroscopic properties. Given that the reflectivity spectrum will be different for each Carbon allotrope, I don't see a simple way how the effect of the atomic radii on reflectivity can be isolated from the variance between allotropes.

    I assume you will be studying different materials, and herein lies the crux of the problem. How can you be certain that the variance you see between samples is due to the atom size and not due to crystal structure or other intermolecular property of the solid you are analysing? One solution could be to use single atoms, however such spectra, as you are probably aware, are difficult to obtain.

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