The Effects of Irradiation On Metals

Applications of electrons with energies in the neighborhood of 1 Mev, changed nucleons such as protons or deuterons, and neutrons in the bombardment of metals to provide information concerning interstitial atoms and vacant sites are discussed. Emphasis is placed on the closepacked noble metals, of which Cu, Ag, and Au are the prototypes. A technique is described for use in the estimation of the effectiveness of incident ratliations in producing displacements of atoms from normal lattice positions. Typical displacement calculations for Cu are presented that were obtained from the simple square-well theory for three typical bombardments. Topics discussed include thermally induced defects in lattice structure, a comparison of lattice and microscopic expansion in metals, the quenching-in of vacancies, and experimental aspects of radiation bombardment. (C.H.)