Neutron Moderation 1 (Research Reactor as Neutron Source)

A thermal neutron reactor produces neutrons of energies in the range of 1-2 MeV, as a result of a nuclear fission reaction of uranium. Neutrons with this high energy range are not suitable for neutron scattering experiments. Therefore, in a research reactor for neutron beam utilization, a thermal moderator is needed to be installed around the primary source to slow down the neutrons to energy levels of 5 meV to 500 meV. Additionally, almost major research reactors equip also at least one cold neutron source, a special moderator operated at cryogenic temperature, which can slow down neutrons to energy levels lower than 5 meV.