'ieutron diffraction experiments -’Pre first performed
over 25 years ago. Klsasser augmented in 1936 that neutrons
could be diffracted by solids, and thio was demonstrated experimentally in the same year by hnlband and Frehwer1', and
Mitchell and Powers, using radium-boryllium neutron sources.
Those early experiments proved that neutrons.. were diffracted
by solids, but did not give quantitative data since the
available neutron sources were of very 1o-t intensity.
Since intense neutron beams have become available
from nuclear reactors, the propertiea of neutrons have been
extensively used to study the solid state. The equivalent
wavelength for low energy neutrons is given by de Broglie’s
equation
