2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/129914The paper analyses volt-ampere characteristics of a planar vacuum diode with mono-energetic electrons, emitted by the cathode (an electron beam). The movement of the electron beam in the volume of the diode is described. An analytic dependence of the volt-ampere characteristics in an unlimited and limited by the field mode of the electron beam is derived.14 pages, 4 figuresGeneral PhysicsClassical Physicstext