General Physics Institute of RAS, Moscow, Russia

Electron bunches dynamics in subpicosecond streak tubes is numerically studied for various initial energy and angular distributions of photoelectrons. It is shown that rather dense nonhomogeneous subpicosecond electron bunch, whose initial energy distribution is narrow enough, tends to disintegrate into two separate bunches due to Coulomb repulsion when traveling in the streak tube from the emitter to the screen. Spatial and temporal broadening of electron bunches generated from the photocathode under the 60 fs incident laser pulses irradiation is studied as a function of initial current density and energy spread of photoelectrons.