Mobility in a strongly coupled dusty plasma with gas

The mobility of a charged projectile in a strongly coupled dusty plasma is simulated. A net force $F$, opposed by a combination of collisional scattering and gas friction, causes projectiles to drift at a mobility-limited velocity $u_p$. The mobility ${\mu }_p=u_p\mathrm{/}F$ of the projectile’s motion is obtained. Two regimes depending on $F$ are identified. In the high force regime, $\mu_p \propto F^{0.23}$,andthescatteringcrosssection$\sigma_s$diminishesas$u_p^{-6/5}$\mathrm{.}Resultsfor$\sigma_s$ are compared with those for a weakly coupled plasma and for two-body collisions in a Yukawa potential. The simulation parameters are based on microgravity plasma experiments.