Question: Figure shows a double-slit interference pattern for neutrons. Neutrons from a nuclear reactor were slowed and then directed into a double-slit apparatus with slit spacing of d = 126 μm and slit width b = 22 μm. When a neutron detector 5m away from the slits was moved perpendicular to the neutron beam, it recorded the interference pattern shown in Fig. Each data point is the number of neutrons detected in 125 min.
a. Using a rule and scale on the figure, find the distance between interference maxima.
b. Find the de Broglie wavelength of the neutrons.
c. What is the neutron velocity?
Fig. - Interference pattern of slow neutrons obtained by Zeilinger et al. Rev. Mod. Phys. 60, 1067 (1988)