Molecular dynamics simulation of a dusty plasma under external electric and magnetic fields*

Being a collection of charged particles (ions, electrons, and dust particles), the dynamics of a dusty plasma can be controlled by the presence of exter- nal electric and magnetic fields. The presence of external electric or magnetic fields is likely to introduce anisotropy in the shielding lengths and the related interactions potentials. Depending on the strength of the external magnetic field, three regimes can be identified: (i) only electrons magnetized, (ii) elec- trons and ions magnetized, and (iii) electrons, ions, and dust particles magne- tized. Here we discuss two types of molecular dynamics simulations: one where electron magnetization leads to anisotropic ion-ion interaction and another one where ion response to a polarity-switched electric field leads to anisotropic dust- dust interaction. The former simulation uses initial conditions relevant to the MDPX experiment at Auburn, while the latter models conditions available at the Plasmakristall-4 facility on the International Space Station. We argue that in both cases, the interaction potentials can be reasonably approximated by a time-independent anisotropic Yukawa potential, i.e., one where the Debye shielding length varies with space.