Neutron Moderation in Nuclear Reactors

This lecture covers the importance of neutron moderation without absorption in nuclear reactors, focusing on the energy dependence of neutron interactions. The instructor explains the concept of slowing down neutrons through elastic collisions, deriving the fractional energy loss per collision. The lecture delves into the energy distribution and angle of deflection, introducing the concept of lethargy as a logarithmic measure of neutron energy. The instructor discusses the average lethargy gain per collision and the competition between slowing down power and absorption. The session concludes with a comparison of different moderators' efficiency in nuclear reactors.