title: Cascade morphology transition in bcc metals.
abstract: 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 (N(F) ~ E(MD)(b)). 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, E(d), is presented for bcc metals.
authors.affiliation: Pacific Northwest National Laboratory, Richland, WA 99354, USA.
authors.forename: Wahyu
authors.initials: W
authors.lastname: Setyawan
authors.forename: Aaron P
authors.initials: AP
authors.lastname: Selby
authors.forename: Niklas
authors.initials: N
authors.lastname: Juslin
authors.forename: Roger E
authors.initials: RE
authors.lastname: Stoller
authors.forename: Brian D
authors.initials: BD
authors.lastname: Wirth
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Kurtz