Abstract
Dust grains in an interplanetary environment can be found generally in two types of locations-floating in a free space and laying on surfaces (e.g., asteroids, comets, Moons). In this study, we focuss on a sputtering process of a dust grain laying on a surface.
As a representative of silicate-type dust we use 1 um spherical SiO_2 particles. The experiment is performed using the Tescan SEM Lyra system when the grain is sputtered by a 30 keV Ga^+ ion beam from the embedded FIB.
A change of the grain shape from spherical to frustum is observed. The sputtering yield is higher at the beginning of the sputtering session and gradually decreases due to grain shape changes.
A simple model of the grain sputtering explains the grain shape development when the modified angular dependence of the sputtering yield is used.