Abstrakt
Dust grains in space are exposed to energetic ions, electrons and UV irradiation. Impact of energetic ions can lead to sputtering of the grain consequently resulting in grain destruction during long-term exposures.
To study such processes we have chosen spherical SiO2 grains with diameters in the range of 1 micrometer as a representative of silicate-type space dust. Our experimental set-up enables us to catch and store a single dust grain which can be sputtered by the ion beam.
The mass of the grain is measured after each sputtering session and we can judge the sputtering eciency from temporal changes of the mass. Our results suggest that the mass change is around 1.5 % per 3-hour bombardment by 1 keV Ar+ ions (current density of 0.2–1.2 mA/m2) which corresponds to the sputtering yield of the order of unity.
An estimation of dust grain survival in solar wind conditions based on our measurement is shown as an application.