Cover Sheet Communication, Signal Processing, Controls Qualifying Exam 2012
Name
Ziad Sobih
NU ID 000-485583 Cell phone 8572042875 Email
[email protected]
Problem 5
X Rays are electromagnetic radiation whose wavelengths are 1 A. Compare this with 550 nm for the center of visible spectrum. In 1912 it is occurred to Max von Laue that a crystalline solid, consisting as it does of regular array of atoms, might form a natural three-dimensional diffraction grating for X rays. The idea is that in a crystal, such as sodium chloride (NaCl),there is a basic unit of atoms (called the unit cell) which repeat itself throughout the array. Figure 22 represents a section through NaCl. It has a cubic structure.
Bragg’s law predicts the condition under which diffracted x-ray beams from a crystal is possible. The dashed lines in figure 2 represent a plane for diffraction. Many other planes can be defined. Figure 3 b shows a family of planes and an incident wave striking them. Each plane act like a mirror. To have constructive interference
We can show that d is related to a. X ray diffraction is a very powerful tool for studying both x ray spectra and the arrangement of atoms in crystals.
X Ray Diffraction from a Single Slit:
X Ray Diffraction from a Double Slit:
X Ray Diffraction from a Multiple Slit:
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