A model study of displacement cascades distributions in zirconium

5 to 200 keV displacement cascades in zirconium are studied in the binary collision approximation with the simulation code Marlowe. The cascades are analysed statistically by means of component analysis, fuzzy clustering and isodata analysis. As a consequence of the large recoil ranges and range straggling specific to open hcp lattices like Zr, a large dispersion of the frequencies of Frenkel pair distributions is found, as well as of the spatial extent and morphology of vacancy and interstitial distributions. In Zr, cascades are formed by a widespread distribution of displacement clusters that can be small. Remarkably, the size and morphology distributions of these clusters are found independent of the primary recoil energy in the energy range investigated.