Abstract: A method for the manufacture of a helix-coupled vane line consists in cutting out, in a part comprising at least one channel, successive slots through the channel that extend beyond the channel so as to obtain portions of turns each fixedly joined to a vane; cutting out, in another part, a succession of fingers that are all fixedly joined to each other; connecting the turn portions to the fingers so that one end of a turn portion is connected to one end of a first finger and the other end of the turn portion is connected to the base of a second finger adjacent to the first finger; and separating the fingers from one another at their bases. Application of helix-coupled vane lines. Is most notably for crossed-field amplifiers.

Abstract: A cooling device for microwave tubes includes a cold part and a heat-conducting member having a first surface in contact with a surface of the cold part. A second surface of the heat-conducting member is in contact with an envelope of the tube. The surface of the cold part and the first surface of the heat-conducting member are respectively concave and convex. The device can be applied to the cooling of microwave tubes including klystrons, travelling-wave tubes and gyrotrons.

Abstract: An electron gun is modulated by an optoelectronic switching device. This switching device comprises a modulated light source and at least one GaAs or Si solid-state optoelectronic switch, this switch being non-conductive when not illuminated and conductive when illuminated by the modulated light source; the device also includes components to transmit the light from the source to the switch(es). In one embodiment, the modulated light source is a laser and in a second embodiment the source is a continuous source externally modulated by a mechanical or electrooptical device. The optoelectronic switching device is connected between a high-voltage source and the cathode of an electron gun, thus modulating the cathode.The invention is particularly applicable to microwave electron tubes.

Abstract: An electron beam generator which can operate in pulse or continuous mode, has an electron beam which is emitted in a main electron gun including a thermionic cathode and an anode. Used in association with this main electron gun is an auxiliary electron gun including a cathode, a grid intended to modulate an auxiliary electron beam in pulses when it is operating in pulse mode or to adjust the current of the auxiliary electron beam when it is operating in continuous mode, and an anode. The anode is in thermal and electric contact with the cathode of the main electron gun. The auxiliary electron beam controls the emission from the cathode. The electron beam emitted by the main electron gun is not disturbed by crossing the grid. Application of the electron beam generator is notably to microwave longitudinal interaction tubes operating at high average and/or peak power.

Abstract: This cathode has a body made of a material that does not emit electrons, having a substantially smooth non-emissive face and elements made of an emissive material each having an emissive face, spaced out from one another and fixed to the body, for example in hollows with their emissive surface in relief by a determined value with respect to said non-emissive face, so that a protection electrode can be placed between the projecting parts of these elements.