Question: When you hold a wire or hair in front of a laser beam you get a diffraction pattern resembling what you get when you pass the laser beam through a slit of the same width.
a. 2eV photons diffracting around a wire as shown in Fig. 15.9 go on to strike a screen 1m away. If the first minimum of the pattern occurs at 6.2mm from the center of the pattern, what is the diameter of the wire?
b. Suppose the wire is 50 μm in diameter and you wish to make the same diffraction pattern with electrons instead of with photons. What energy must the electrons have to produce a first minimum 6.2mm from the center of the pattern?
Fig. - Light diffracting around a wire
c. Suppose instead of a great, huge, thick wire, you had a wire of the diameter of a nucleus, i.e., ≈10-14 m. What energy would the electrons have to have in order to produce a diffraction minimum 6.2mm away from the central maximum on a screen 1m away?
d. If the second maximum occurs at 9mm, what is the angle through which the photons or electrons have been scattered to reach that point on the screen? Give your answer in radians.