Derling-Tseng, U-M research associate from Formosa (Nationalist China), operates equipment to make electron spin resonance measurements of radiation damage at Phoenix Memorial Laboratory Building. Radiation, such as neutrons can produce changes in material characteristics either by changing the chemical composition or by changing the structure. Knowledge of these changes is necessary to anticipate and compensate for damage which may occur in devices which operate in intense sources of radiation such as reactors. The black discs at right are part of a large magnet.