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 research leading to the development of new materials and to the solution of a wide range of fundamental and applied problems in solid-state science through the application of modern methods for the synthesis and characterization of ceramics, glasses, and alloys and the growth of single crystals.
For playing a substantial and lead role in developing and establishing the structural design methodology that is vital to safe and reliable nuclear power, including the development of high-temperature design analysis methods and code rules that are used worldwide.
For basic studies in the fracture of and toughening mechanisms in ceramics and ceramic composites, in the establishment of the relationships between microstructure and composition and mechanical behavior, and in the development of advanced ceramic materials.
For contributions to understanding plasma turbulence and the nonlinear properties of magnetohydrodynamic instabilities, especially their role in explaining the behavior of magnetically confined plasmas, and for development of new magnetic confinement concepts that overcome these limitations.
For contributions to the development of new concepts and advanced systems for power generation and conversion, through innovative designs of nuclear reactors for aircraft propulsion and space auxiliary power and concepts for thermonuclear fusion reactor power plants
For original studies of the genetic effects of radiation in mammals. A world authority on mammalian mutagenesis, he and co-workers provided the experimental basis for estimating the genetic hazards of radiation to man and for the corresponding recommendations of national and international standards bodies