Cycloid motions of grains in a dust plasma
Zhang Yong-Liang, Feng Fan, Liu Fu-Cheng, Dong Li-Fang, He Ya-Feng†,
       

Schematic diagram of the inverse (normal) Magnus force FMI (FMN) acting on a spinning grain. In the free molecular flow regime, P (P′) represents the pre-impact momentum (deflected momentum).