HR: 17:35h
AN: SA54A-05    [Abstracts]
TI: Modification of Spherical Dust Grain Structure: Laboratory Simulation
AU: * Richterova, I
EM: ivana.richterova@mff.cuni.cz
AF: Charles University, Faculty of Mathematics and Physics, V Holesovickach 2, Prague, 180 00, Czech Republic
AU: Fujita, D
EM: Fujita.Daisuke@nims.go.jp
AF: National Institute for Materials Science, Tsukuba 305-0044, Tsukuba, 305-0044, Japan
AU: Onishi, K
EM: Onishi.Keiko@nims.go.jp
AF: National Institute for Materials Science, Tsukuba 305-0044, Tsukuba, 305-0044, Japan
AU: Pavlu, J
AF: Charles University, Faculty of Mathematics and Physics, V Holesovickach 2, Prague, 180 00, Czech Republic
AU: Safrankova, J
EM: jana.safrankova@mff.cuni.cz
AF: Charles University, Faculty of Mathematics and Physics, V Holesovickach 2, Prague, 180 00, Czech Republic
AU: Nemecek, Z
AF: Charles University, Faculty of Mathematics and Physics, V Holesovickach 2, Prague, 180 00, Czech Republic
AB: Sputtering of astrophysical grain material is often discussed process leading to grain erosion or destruction. The compositional change resulting from implantation of energetic ions into the grain material influences not only the sputtering rate but it changes electrical properties of the dust grains. Consequently, the grain charge and its dynamics in space electric and magnetic fields can be modified. In this contribution, we compare the results of a study of surface structure and its change due to surface modification by high-energy ion (Ar, He) beams on different samples. For these experiments, we have chosen a micron-sized spheres as well as planar films and/or monocrystal of gold. A choice of this material follows from the fact that the composition of dust grains in the space is rather complicated and basic material constants of space relevant materials are unknown, thus Au samples seem to be suitable for our preliminary study. To detail investigations of surface properties, both the method of stored single grain influenced by the ion beams and the techniques of the scanning electron microscopy were applied. In-situ Auger analysis is used to observe changes in surface composition, especially the Ar implantation. As a result, the sputtering yields and precise spectra of secondary electrons in a wide energy range on samples are discussed.
DE: 2129 Interplanetary dust
DE: 2461 Plasma interactions with dust and aerosols (7849)
DE: 5759 Rings and dust
DE: 6015 Dust
SC: SPA-Aeronomy [SA]
MN: 2007 Joint Assembly