[en] For relativistic electron beam shaping by means of strong magnetic compression for the beam current density of the order of 10³ A/cm² it is possible that selection of a magnetic field configuration when without substantial distortion of electrostatic compression in the diode part of an electron-optical system is realized in the anode aperture a smooth 'picking up' of the beam and than effective magnetic compression in an extended channel in conditions of strong magnetization with admissible limitations for electron oscillations