Abstract: A system for detecting and counting ions comprises a source of atoms, a hot filament ion source, means for generating an electric field and a magnetic field, and means for detecting and counting the ions, and the filament comprises a portion that is concave along its longitudinal and/or transverse axis.

Abstract: A system for detecting and counting ions comprises a source of atoms, a hot filament ion source, means for generating an electric field and a magnetic field, and means for detecting and counting the ions, and the filament comprises a portion that is concave along its longitudinal and/or transverse axis.

Abstract: The invention relates to amplifying electron tubes operating at microwave frequencies. The electron tube comprises: a pump-out tube that allows the vacuum inside the electron tube to be created; an electron gun that emits an electron beam inside the electron tube; a collector that directly collects a first portion of the electron beam. The pump-out tube directly repels a second portion of the electron beam in the direction of the collector.

Abstract: The invention relates to amplifying electron tubes operating at microwave frequencies. The electron tube comprises: a pump-out tube that allows the vacuum inside the electron tube to be created; an electron gun that emits an electron beam inside the electron tube; a collector that directly collects a first portion of the electron beam. The pump-out tube directly repels a second portion of the electron beam in the direction of the collector.

Abstract: The invention concerns the electronic amplifier tubes operating at radio-frequency. The electronic tube includes a long tubular sleeve containing an electron beam, a housing supporting the sleeve mechanically, and means to provide heat transfer from the sleeve to the housing to cool the sleeve. The means to provide the heat transfer include a resin filling a free volume located between the sleeve and the housing.

Abstract: Disclosed is a method for the construction of helix travelling wave tubes in which the helix is supported by insulating dielectric supports, wherein the dielectric supports, in turn, are supported by support-forming elements which project from the internal wall of the vacuum-tight casing surrounding the set, towards the helix, thus reducing the radial dimensions of the dielectric supports. In most of the embodiments, these novel support-forming elements are made of metallic material. The disclosed method greatly simplifies the construction of delay lines with low dispersion for travelling wave tubes with very great bandwidth while, at the same time, increasing the precision of assembly that can be obtained. An additional advantage of the reduction of the radial dimensions of the dielectric lies in an improvement of the possibilities of thermal conduction from the helix to the casing that surrounds the set.

Abstract: A microwave tube provided with at least one axial part, supported by at least three spacers and fitted cold into a coaxial envelope. The internal surface of the envelope or the external surface of the part comprises a relief designed to block a spacer so that the assembly formed by the part and the spacers is clamped in the envelope. The blocking is obtained by a relative shift between at least one spacer and the surface comprising the relief. The axial part may be the gun or the collector of a longitudinal-interaction tube or the delay line of a travelling-wave tube.

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.

Abstract: The disclosure concerns microwave tubes and, more particularly, travelling wave tubes wherein the region under vacuum is isolated from the external HF input/output circuits by vacuum-tight windows. The disclosed window consists of a ceramic cylinder, the two ends of which bear metallic flexible rings. This window is brazed to the cylindrical chamber of the part under vacuum by means of a clearance machined in the chamber, so that the chamber and the window are integrated and coaxial. The HF transmission through the window is achieved by means of an antenna formed by a metallic strip mounted, at right angles, on a metallic cylinder that fits the chamber. The device can be applied to power microwave tubes and, notably, to travelling wave tubes.

Abstract: In a travelling wave tube, the delay line of which is coupled to a transmission line of an external microwave circuit by a coupling pin having a coupling surface that faces an end surface of the transmission line, a microwave window extends between the coupling surface of the coupling pin and the end surface of the transmission line. This window is permeable to the microwave energy and impermeable to the gases. It is fixed imperviously to the travelling wave tube.