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 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 applying molecular beam techniques to study chemically reactive collisions, helping to lay the foundation for the present field of chemical dynamics, and for pioneering studies in accelerator-based atomic physics, ion-solid interactions, and the channeling of ions, electrons and positrons in crystalline solids.
For discoveries of fundamental importance in mammalian genetics, as well as for studies of genetic and developmental effects in mice, which have provided a broad basis for assessment of the genetic risk to humans from radiation and chemicals, including the development of genetic and early developmental tests now used worldwide.