In Fig. 36-51, let a beam of x rays of wavelength 0.125 nm be incident on an NaCl crystal at angle θ...

In Fig. 36-51, let a beam of x rays of wavelength 0.125 nm be incident on an NaCl crystal at angle θ = 45.0° to the top face of the crystal and a family of reflecting planes. Let the reflecting planes have separation d = 0.252 nm. The crystal is turned through angle ? around an axis perpendicular to the plane of the page until these reflecting planes give diffraction maxima. What are the (a) smaller and (b) larger value of ? if the crystal is turned clockwise and the (c) smaller and (d) larger value of ? if it is turned counterclockwise?

Fig.36-51