Abstrakt
Dust coexists with plasma of various parameters in space as well as in laboratories and industrial facilities. The mutual interaction of plasma particles with dust grains leads to their charging.
An equilibrium grain potential depends on plasma environment as well as on the grain composition, size, shape, and history. A precise estimation of an equilibrium grain potential in a specific plasma environment can be thus complicated.
We present results of a new numerical method for calculation of an equilibrium potential of the grain immersed in the plasma simulating a lunar environment where an influence of secondary electron emission by energetic electrons increases during the Earth plasma sheet crossings. In calculations, we apply a modified model of secondary electron emission for dust grains which takes into account an influence of grain size, material, and surface roughness.
Since this model describes the increase of the secondary emission yield caused by a finite dimension of the dust grain, our calculations provide a more realistic estimation of the dust grain charge in hot environments.