No CrossRef data available.
Published online by Cambridge University Press: 12 April 2016
The penetration of energetic particles from stellar winds, cosmic rays and fast moving gas clouds in interstellar dust grains induces a variety of physical and chemical changes. Detailed information on penetration ranges, number of secondary projectiles produced by knock-on and their energy distribution is obtained from computer simulation of collision cascades with the program MARLOWE. Model targets are polycrystalline H2O-ice, NH4Cl, and SiO2, projectiles are lo2 - lo4 eV H, He, and C. Depending on the energy and the projectile/ target mass ratio up to lo2 secondary projectiles are created per primary impact with energies ranging from a few to some lo3 eV. In composite grains, condensed gases and ice mixtures the energetic secondaries can undergo hot chemical reactions leading to a series of precursors for larger organic and biomolecules.