HR: 0800h
AN: SH51D-0297    [Abstracts]
TI: Can cosmic rays amorphize silicate dust particles?
AU: * Bringa, E M
EM: ebringa@llnl.gov
AF: Lawrence Livermore National Laboratory, 7000 East Ave., L-371, Livermore, CA 94550 United States
AU: Bajt, S
EM: bajt1@llnl.gov
AF: Lawrence Livermore National Laboratory, 7000 East Ave., L-371, Livermore, CA 94550 United States
AU: Baragiola, R A
EM: raul@virginia.edu
AF: University of Virginia, Engineering Physics Department, Charlottesville, VA 22903 United States
AU: Bradley, J
EM: jbradley@igpp.ucllnl.org
AF: Lawrence Livermore National Laboratory, 7000 East Ave., L-371, Livermore, CA 94550 United States
AU: Dai, Z
EM: dai1@llnl.gov
AF: Lawrence Livermore National Laboratory, 7000 East Ave., L-371, Livermore, CA 94550 United States
AU: Dukes, C
EM: car8r@virginia.edu
AF: University of Virginia, Engineering Physics Department, Charlottesville, VA 22903 United States
AU: Felter, T
EM: felter1@llnl.gov
AF: Lawrence Livermore National Laboratory, 7000 East Ave., L-371, Livermore, CA 94550 United States
AU: Graham, G
EM: graham42@llnl.gov
AF: Lawrence Livermore National Laboratory, 7000 East Ave., L-371, Livermore, CA 94550 United States
AU: Kucheyev, S
EM: kucheyev1@llnl.gov
AF: Lawrence Livermore National Laboratory, 7000 East Ave., L-371, Livermore, CA 94550 United States
AU: Loeffler, M J
EM: mjl8r@cms.mail.virginia.edu
AF: University of Virginia, Engineering Physics Department, Charlottesville, VA 22903 United States
AU: Tielens, A
EM: tielens@astro.rug.nl
AF: University of Groningen, Kapteyn Astronomical Institute, Groningen, 9700 Netherlands
AU: Torres, D
EM: torres25@llnl.gov
AF: Lawrence Livermore National Laboratory, 7000 East Ave., L-371, Livermore, CA 94550 United States
AU: VanBreugel, W
EM: wil@igpp.llnl.gov
AF: Lawrence Livermore National Laboratory, 7000 East Ave., L-371, Livermore, CA 94550 United States
AB: Interstellar and interplanetary dust plays a key role in the evolution of the Interstellar Medium (ISM) in galaxies and the formation of stars, planets and possibly life. The dust composition is determined by physical processes, including ion bombardment. We have irradiated forsterite single crystals dust analogs with swift heavy ions with a large electronic energy deposition. Amorphization of the crystals was monitored with Rutherford Back-Scattering (RBS) and verified by transmission electron microscopy (TEM) observations. Modeling of ion tracks also shows a similar behavior. IR spectra of the irradiated samples agree well with observed astronomical spectra. Based on this evidence, and taking into account accepted ion fluxes we can predict that silicate grains can be amorphized by heavy cosmic rays.
DE: 2104 Cosmic rays
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2004 AGU Fall Meeting