Abstract: A cooling arrangement for an electron collector of an electron beam tube has a plurality of solid dielectric spacers surrounding the corrector with an electrically insulative and thermally conductive dielectric liquid in gaps between the spacers. A water cooling system is arranged in thermal contact with the spacers and the liquid dielectric to provide cooling by water circulation. The cooling arrangement is a hybrid of oil and water cooling systems in which the electrically non conductive oil is arranged in gaps between dielectric spacers, the dielectric spacers provide a support for the surrounding water coolant system and ordinary water may be used to be pumped through the water cooling system.

Abstract: An inductive output tube includes a capacitative tuner in the form of a plunger which is moveable inside the integral output cavity of the inductive output tube so as to vary the capacitance between an input and output drift tube and hence the resonant frequency of the output stage. The tuning plunger is moveable by protruding through a wall of the vacuum envelope of the output cavity, so as to allow the capacitance to be changed by operation of the tuning plunger by manual or automatic means from outside the cavity.