Mook has conducted neutron scattering research on a broad spectrum of materials. He is best known for his pioneering research on the magnetic excitations of transition metal ferromagnets and the observation of itinerant electron effects in these materials.
For innovative and fundamental contributions to the understanding of the interactions and transport of electrons in gases and liquids, negative ion processes, the interfacing of the gaseous and condensed phases of matter, and the use of fundamental knowledge in the development of gaseous dielectrics, radiation detectors, and pulsed power
For fundamental studies of the microscopic structure of magnetic materials using neutron scattering methods, and for contributing to the development of neutron polarization analysis as a productive scientific technique.
For fundamental studies in radiation physics, radiation dosimetry, and surface physics and for pioneering theoretical work on collective electron modes, surface electromagnetic waves in solids, and elucidation of the interaction of charged particles with matter.