Effect of truncation of electron velocity distribution on release of dust particle from plasma-facing wall

In modeling of release of a dust particle from a plasma-facing wall it is usually assumed that electron velocity distribution is Maxwellian. However, the absorption of fast electrons by the conducting wall can lead to truncation of fast component of reflecting electrons from the wall. In this work we study the effect of truncation of electron velocity distribution on the release condition of a conducting spherical dust particle from the plasma-facing wall. The truncation increases the electric field at the wall surface compared to that calculated in absence of the truncation. The stronger electric field makes the dust particle hard released when the gravitational force is directed from the wall and applied wall potential is shallower than the floating one.