Squeezed states of high-current electron beam in a system with virtual cathode

Introduction It is well-known that the dependence of electron beam potential on its current is a two-valued function [1], i.e., in theory, there are two states of a beam with a given current. Only one of them corresponding to the lower density and higher velocity exhibits itself in both physical and computer experiments. Another beam state with higher density and lower velocity, which is called here a squeezed one, is usually supposed to be unstable. Moreover, it wasn´t quite clear which way one could prepare such a state.