Neutron optics studies the interactions of a beam of slow neutrons with matter. This book updates various advances on neutron optics. There will be a focus on the very active topics of neutron imaging (NI) and neutron spin optics (NSO). The book will also present applications of neutron beams in biomedicine, such as Boron Neutron Capture Therapy (BNCT) and related techniques. Features: Discusses diffraction and interference of slow neutrons, including computational approaches Reviews neutron imaging (NI) and neutron spin optics (NSO) Treats two major sources of slow neutron beams: (1) fission reactions at nuclear reactors and (2) collisions in particle accelerators (small ones, spallation sources) of charged particle beams with targets of heavy atoms Selects subjects on fundamental quantum aspects of slow neutrons and on confined propagation and waveguiding thereof Updates slow neutron beams and BNCT