- #1
cahill8
- 31
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Homework Statement
I am inquiring about Braggs Law [tex]2 d\sin\theta = n\lambda [/tex].
The question I'm working on gives me the first four Bragg angles ([tex]\theta[/tex] values) and I have also calculated the wavelength of the light. I want to solve for d but I am unsure what value to use.
Homework Equations
Rearranging for d: [tex]d = \frac{n\lambda}{2\sin\theta} [/tex]
The Attempt at a Solution
I seem to have multiple options. Using the different [tex]\theta[/tex] values with the corresponding n value (n=1,2,3,4) gives a different answer for d each time. I'm not sure whether to use just the first value ([tex]\theta_1[/tex] and n=1) or whether I should sum them all and divide by 4 to get an average? This site http://www.bruker-axs.de/fileadmin/user_upload/xrfintro/sec1_8.html (1/4 of the way down) suggests that each [tex]\theta[/tex] and corresponding n value account for different reflection orders. To me this sounds like the best value would be getting the average but I just want to make sure.
i.e. [tex]d = \frac{1}{4}\left(\frac{\lambda}{2\sin\theta_1}+...+\frac{4\lambda}{2\sin\theta_4}\right) [/tex]
What do you think?