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Homework Help: X-Ray Diffraction Equation (Mineralogy HW)

  1. Mar 31, 2010 #1
    1. The problem statement, all variables and given/known data
    Okay so, I was hoping someone out there might be able to assist me with a Mineralogy problem I have. The concept is based around X-Ray Diffraction.

    The question:

    Derive a diffraction equation from the illustration below that relates the reflection angle (theta) to the wavelength (lambda) and the d spacing (d). Show all of your work so that it is clear that you understand the physics and the math in this important derivation.

    Here is a picture of the diagram given...sorry for the poor quality :)

    I've been banging my head against this for two days now, and I just dont seem to be getting anywhere with this...Ive tried google, my book, everything at my disposal, I just cant seem to figure this out at all...I am at a stand still because there are 5 other questions related to this problem, but i need to solve this first...can anyone help...Thanks in advance for your time! :)
  2. jcsd
  3. Apr 1, 2010 #2


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    Staff: Mentor

    I guess it is not for any theta, but for a specific value of theta? One that gives some observable effect? For that effect to happen - is there anything you can tell about FG?

  4. Apr 1, 2010 #3
    Start with one of the fundamental considerations:
    in terms of that diagram, what are the conditions for constructive vs. destructive interference of the reflected waves?
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