Stable three-dimensional Langmuir vortex soliton

We present a numerical solution in the form of a three-dimensional (3D) vortex soliton in unmagnetized plasma in the model of the generalized Zakharov equations with saturating exponential nonlinearity. To find the solution with a high accuracy we use two-step numerical method combining the Petviashvili iteration procedure and the Newton-Kantorovich method. The vortex soliton with the topological charge $m=1$ turns out to be stable provided the nonlinear frequency shift exceeds a certain critical value. The stability predictions are verified by direct simulations of the full dynamical equation.