Stabilization of Relativistic Electron Beam by Dense Plasma Cloud in GOL-3 Expander

The paper presents new experimental results from the GOL-3 facility on stabilization of some beam instability modes by controlled conditions at an exit beam receiver. In the experiments the space near the beam collector in the exit expander was filled with krypton. Position and shape of the beam footprint at the exit collector was imaged using the beam bremsstrahlung. The beam shape changes were detected by a set of magnetic probes. Improvement of the beam stability due to krypton puffing was achieved. Possible mechanisms of such stabilization are discussed.