Energetic atom collisions in solids induce shockwaves with complex morphologies. In this paper, we establish the existence of a morphological transition in such cascades. The order parameter of the morphology is defined as the exponent, b, in the defect production curve as a function of cascade energy (NF∼EMDb). Response of different bcc metals can be compared in a consistent energy domain when the energy is normalized by the transition energy, μ, between the high- and the low-energy regime. Using Cr, Fe, Mo and W data, an empirical formula of μ as a function of displacement threshold energy, Ed, is presented for bcc metals.
@article{arxiv.1412.7452,
title = {Cascade morphology transition in bcc metals},
author = {Wahyu Setyawan and Aaron P. Selby and Niklas Juslin and Roger E. Stoller and Brian D. Wirth and Richard J. Kurtz},
journal= {arXiv preprint arXiv:1412.7452},
year = {2015}
}