Binary collision calculation of subcascade structure and its correspondence to observed subcascade defects in 14 MeV neutron irradiated copper

Abstract

A model calculation of subcascade structure in copper, based on the binary collision approximation using MARLOWE code, is made. The primary recoil energy spectrum by 14 MeV neutron irradiation and the threshold type subcascade energy of 10 keV are employed. The calculated results of the number of subcascades and the distance between subcascades show good agreement to reported experimental analysis. Distribution of the calculated cascade zone size extends towards larger size much more than that experimentally obtained for thin foil irradiation. This difference is understood as the under estimation in experimental measurement owing to the limitation by the thickness of the microscopically observable specimen foil (< 100 nm). Distribution of subcascade structure produced by monochromatic primary recoil energy is examined by the same calculation model. Primary recoil energy dependence of subcascade structure is also examined. The usefulness and the limitation of the present model calculation is discussed.