Neutron transmission: A powerful technique for small accelerator-based neutron sources

The determination of total cross section of a material as a function of neutron energy by means of transmission experiments is rather easy on a pulsed neutron source. The spectrometer and associated instrumentation required may be described as relatively simple, and sound statistical data are achieved even using a small, pulsed, accelerator based neutron source. Despite its simplicity, detailed scientific and technological information can be extracted from such measurements, at the cost of fairly elaborate data analysis techniques. These features make this an attractive tool for neutron-based materials research within small research groups. Different physical properties of a material manifest over the different neutron energy ranges. At our group we have focused on the determination and analysis of the total cross section for thermal and sub-thermal neutrons, which is very sensitive to the geometric arrangement and movement of the atoms, over distances ranging from the’ first-neighbour scale’ up to the microstructural level or’ grain scale’.