Theoretical background
Diffraction et spectrométrie des neutrons

It was the work of E. Fermi, C.G. Shull and N.B. Brockhouse [1, 2, 3] that essentially gave rise to neutron diffraction and spectrometry. This technique has become a classic [4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14] method for studying the microscopic structure of matter, very similar to the older methods of light and X-ray scattering (see [67, 68] in Techniques de l'Ingénieur), for which it complements many of the applications. Its originality lies in the properties of neutrons.

A neutron is a particle whose mass m = 1.675.10 ^-27 kg is 1,836 times that of the electron, whose electric charge is zero and whose spin σ is 1/2. A neutron's energy E is related to its velocity v by the relation $E=\frac{1}{2}m{v}^2$....