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| Titel |
Sputtering of dust grains in free space and on the surface |
| VerfasserIn |
Marek Vysinka, Jakub Vaverka, Jiri Pavlu, Jana Safrankova, Zdenek Nemecek |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250104512
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| Publikation (Nr.) |
 EGU/EGU2015-3934.pdf |
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| Zusammenfassung |
| Dust grains in an interplanetary environment can be found generally in two
modifications—floating in a free space and lying on surfaces (e.g., of asteroids, comets,
Moons). In both forms, they can be exposed to energetic ions, electrons, and UV
irradiation and these processes lead to their charging and sputtering. The floating
grain can rotate along all its axes, thus it can be sputtered isotropically, on the other
hand, the grain lying on the surface cannot move and it is exposed from one side
only. This process leads to non-regular grain sputtering and to changes of a grain
shape. To study of the sputtering of both freely floating and lying grains, we used
spherical SiO2 grains with diameter in the range of 1Âmicron as a representative of the
silicate-type space dust. For the floating grain we use the experimental set-up that in
which a single dust grain levitates in an electrodynamic trap and it is influenced by
3ÂkeV Ar+ ions (due to the grain charge, the impact energy corresponds to approx.
2ÂkeV). The mass of the grain is measured after each sputtering session and the
sputtering yield is calculated from the temporal changes of its mass. On the other
hand, the laying grain is sputtered by 30ÂkeV Ga+ ions and SEM images of the
grain are recorded in regular time intervals. The sputtering yield is estimated from
changes of the grain shape and the final shape is compared with a simple model. |
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