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Chapter 47: Problem 34

Question: In comparing the wavelengths of two monochromatic x-ray lines, it is noted that line A gives a first order reflection maximum at a glancing angle of $\theta_1~=~23.3^o$ , to the face of the crystal. Line B, known to have a wavelength $\lambda~=~96.7~{\rm nm}$ ., gives third order reflection maximum at an angle of $\theta_2~=~58.0^o$ from the same face of the same crystal.

1.: Calculate the interplane spacing.
2.: Find the wavelength of line A.

Solution: From Braggs law fro line B, we have that

$\displaystyle d~=~{3\lambda\over 2 \sin\theta_3}~=~0.171~{\rm nm}$

from which we find that

$\displaystyle \lambda_A~=~{2 d \sin\theta_1\over 1}~=~0.134~{\rm nm}$

Martin Savage
1999-03-10