ABSTRACT
This chapter aims to study electromagnetic current-driven instabilities and the effect of a magnetic-field inhomogeneity on the electrostatic current-driven instabilities. There are two possible reasons for small-scale instabilities in a plasma with a transverse current: first, the usual drift effects due to density and temperature inhomogeneity, and second, the relative motion of electrons and ions associated with the current. The chapter discusses the role of a transverse current in the lower-hybrid-drift instability in a finite–βplasma. It considers the electron-acoustic oscillation branches and their electromagnetic modification. The chapter deals with the electrostatic current-driven electron-acoustic instability and the corresponding type of electromagnetic current-driven instabilities. It provides the ion-cyclotron perturbations in a finite–β rotating plasma. The chapter discusses gradient instabilities in the absence of additional current. Certain current-driven instabilities can be considered to be electrostatic and can be studied in the approximation of a homogeneous plasma and a homogeneous magnetic field.
