Kinetic theory of $\mathrm{sech}^2x$ electron holes and applications to Kappa-distributed plasmas

Abstract

The kinetic theory of $\mathrm{sech}^2 x$-type electron holes is studied. The potential of the electron holes is solved in the weak amplitude limit by the pseudo-potential method. We investigate the existence condition of the $\mathrm{sech}^2 x$ electron holes. It indicates that the derivatives of trapped and untrapped distributions at the separatrix play significant roles in determining the potential profile. The theory is then applied to the Kappa-distributed plasmas. The amplitude and width of the $\mathrm{sech}^2 x$ electron holes are analyzed. Finally, the theoretical results are verified by numerical calculations.