Squeezed State as a "Quasi-Neutral" One-Component Plasma

We present a one-dimensional model which gives a novel physical interpretation of the specific equilibrium state of the magnetized electron cloud in the Malmberg-Penning trap. In the model, the strong magnetic field prevents radial expansion of the electrons, while the electrostatic potential well restricts their axial motion. A force-free steady-state is formed when the space-charge field of the electrons accumulated in the potential well, compensates the external electrostatic field. This state is known in another context as a squeezed state. It is shown that the equilibrium electron density distribution is correlated to the potential well's shape. Small perturbations of the steady-state survive over a long period of time in the form of specific propagating waves.