A method of activating a plurality of stages (14, 16, 18) of cascading electron tubes within a common vacuum enclosure (12), the method comprising: a) interconnecting the plurality of stages 14, 16, 18) of cascade electron tubes in series, from a non-final stage (14, 16) to a final stage (18), such that in each non-final stage an electrode (14a, 16a) is connected to an electrode (16c, 18c) of a following stage by a respective electrical interconnection (20, 22)； b) at least one of said respective electrical interconnections comprises a link structure (20, 22) for electrically and mechanically joining an electrode (14a, 16a) of a previous stage with an electrode (16c, 18c) of a following stage； said link structure (20, 22) being the primary mechanical support for said electrode (14a, 16a) of the previous stage and for said electrode (16c, 18c) of the next stage, the electrode of the previous stage comprising an anode ( 16a, 18a) and the cathode (16c, 18c) comprising the electrode of the next stage； c) placing the plurality of cascade electron tube stages within the common vacuum enclosure (12) and aspirating air from the enclosure； and d) providing an electrical voltage between the cathode (16c) and the anode (14a), the electrodes being, of a first stage connected in series of said cascade electron tube stages, to supply electrical energy to the first stage； said energy being propagated in series through an intermediate stage to the final stage to facilitate the activation of all tube stages.Un método de activación de una pluralidad de etapas (14, 16, 18) de tubos de electrones en cascada dentro de recinto de vacío común (12), comprendiendo el método: a) interconectar la pluralidad de etapas 14, 16, 18) de tubos de electrones en cascada en serie, desde una etapa no final (14, 16) hasta una etapa final (18), de tal modo que en cada etapa no final un electrodo (14a, 16a) es conectado a un electrodo (16c, 18c) de una etapa siguiente por una respectiva interconexión eléc
