title: IM3D: A parallel Monte Carlo code for efficient simulations of primary radiation displacements and damage in 3D geometry.
abstract: SRIM-like codes have limitations in describing general 3D geometries, for modeling radiation displacements and damage in nanostructured materials. A universal, computationally efficient and massively parallel 3D Monte Carlo code, IM3D, has been developed with excellent parallel scaling performance. IM3D is based on fast indexing of scattering integrals and the SRIM stopping power database, and allows the user a choice of Constructive Solid Geometry (CSG) or Finite Element Triangle Mesh (FETM) method for constructing 3D shapes and microstructures. For 2D films and multilayers, IM3D perfectly reproduces SRIM results, and can be ∼10(2) times faster in serial execution and > 10(4) times faster using parallel computation. For 3D problems, it provides a fast approach for analyzing the spatial distributions of primary displacements and defect generation under ion irradiation. Herein we also provide a detailed discussion of our open-source collision cascade physics engine, revealing the true meaning and limitations of the "Quick Kinchin-Pease" and "Full Cascades" options. The issues of femtosecond to picosecond timescales in defining displacement versus damage, the limitation of the displacements per atom (DPA) unit in quantifying radiation damage (such as inadequacy in quantifying degree of chemical mixing), are discussed.
authors.affiliation: Key Laboratory for Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei, 230031, China.|Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, 02139, USA.|University of Science and Technology of China, Hefei, 230026, P. R. China.
authors.forename: Yong Gang
authors.initials: YG
authors.lastname: Li
authors.affiliation: Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, 02139, USA.
authors.forename: Yang
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, 02139, USA.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Short
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale and Department of Physics, University of Science and Technology of China, Hefei, 230026, P. R. China.
authors.forename: Ze Jun
authors.initials: ZJ
authors.lastname: Ding
authors.affiliation: Key Laboratory for Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei, 230031, China.|University of Science and Technology of China, Hefei, 230026, P. R. China.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Zeng
authors.affiliation: Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, 02139, USA.
authors.forename: Ju
authors.initials: J
authors.lastname: Li