Abstract: The invention is a mode converter and power splitter device for electron tubes, particularly gyrotrons and tubes of similar categories. These tubes have an output cavity 2, which is a circular form about a centerline, and a hollow electron beam 1 which propagates along the same centerline. The device complying with the invention is a structure which comprises secondary wave guides 6, symmetrical in azimuth around the same centerline as the outlet cavity, each guide 6 containing coupling apertures 7 on its outer wall (that furthest from the centerline), these apertures 7 being arranged to excite a given mode in the guide. One important embodiment of the invention is that the electron tube operates in a TE.sub.m,n mode with a high azimuth index m and the number of secondary guides 1=m. Another important embodiment of the invention is that secondary guides 6 are trapezoidal in section. Another important embodiment of the invention is that secondary guides 6 are excited in the fundamental mode.

Abstract: Disclosed is a directional coupler on a mirror elbow for a microwave transmission line sized to convey very high power. The coupler consists of a main guide with a mirror elbow and at least one secondary guide. The secondary guide is joined by one of its walls to the external surface of the mirror, and the interior of the secondary guide is joined to the interior of the mirror elbow by coupling holes.

Abstract: Disclosed is a microwave tube with n (where n is an integer greater than one) longitudinal electron beams parallel to an axis XX'. It has at least one output cavity crossed by the electron beams and one collector collecting the n electron beams at their output from the cavity. A transmission line is coupled to the output cavity. The transmission line is coaxial with the axis XX'. The collector is positioned around the transmission line and is coaxial with it. The device can be applied to multiple-beam klystrons capable of working at high power and at high frequency.

Abstract: Disclosed is a microwave tube with n (where n is an integer greater than one) parallel, longitudinal electron beams distributed on a ring centered on an axis XX'. The electron beams go through several groups of n cavities. So that each group may resonate on a single frequency, it is provided that the cavities of one and the same group will work in their dominant mode, at one and the same frequency, and will get excited in phase. To this end, the cavities of the input group are excited in phase by an appropriate device external to the tube. The device can be applied to multiple-beam klystrons working at high frequencies.

Abstract: The present invention is directed to a mode transformer for a microwave energy transmission circuit. This transformer is interposed between an electromagnetic wave source, operating in a predetermined frequency band, and a waveguide transmitting energy. This waveguide is excited by the electromagnetic wave source in a single chosen mode. The transformer has the shape of a conical tube whose large end is connected to the waveguide. The electromagnetic wave source is connected to the conical tube by a lateral opening. In the region of the conical tube where the excitation takes place the cross-section of the conical tube is smaller than that of the waveguide. At the center of the lateral opening, the cross-section of the conical tube is that which would be that of a waveguide of the same shape whose cut-off frequency, for the chosen mode, would be the central frequency of the working frequency band.

Abstract: A system of at least three concave mirrors (M1, M2, M3 . . . ) of cylindrical form are arranged with the concave part of the first mirror M1 facing towards the second mirror M2 and with the planes defined by the straight sections of the two mirrors which are perpendicular to each other. The arrangement further has the concave part of the third mirror M3 facing towards the second mirror M2 with the planes defined by the straight sections of the two mirrors M3, M2 perpendicularly to each other. Successive mirrors are placed in a crosswise fashion with respect to their nearest neighbor in order to provide for applications in the guiding of millimeter and sub-millimeter electromagnetic waves for plasma physics.

Abstract: A trajectory correcting device for electron tubes comprises an auxiliary trajectory correcting means capable of creating a magnetic field that corrects the effects of azimuthal drift of the beam between a first disk and a second disk. This drift is due to the non-uniformity of the main field between the two disks. This means may include several coils, through which currents flow, placed in the vicinity of the disks or between them. The device can be applied to multibeam klystrons.

Abstract: According to the invention, the conducting collector wall (23) on which the electrons are collected is surrounded by a coil winding (36) which is supplied with a periodically varying current, creating a slightly divergent axial magnetic field whose amplitude is periodically variable with time. The electron trajectories strike the collector wall at a grazing, nearly tangential angle, broadening the zone of impact, and the zone of impact is swept back and forth along the length of the collector, further spreading the power to be dissipated on a greater surface of the collector. Application to realization of very high power tubes or moderate power tubes with reduced collector dimensions.

Abstract: A generator of short electromagnetic waves is provided with a novel form of resonant cavity having improved mode selectivity. The reflecting walls of the cavity correspond to a surface of revolution and the meridian planes include four discrete mirror zones which face each other and are positioned so that the centers of the mirror zones form the vertex of a polygon and the normals to said mirror zones at the centers are bisectors of the angles formed at the vertices of the polygon.

Abstract: This transformer (9) is formed by a waveguide, of approximately elliptical cross-section, and with increasing eccentricity (e) along the axis (z) of the transformer. This transformer (9) is connected on one side to the cavity (1) of a gyrotron (11) and on the other side to a section of guide (13) having the same cross-section as the final cross-section of the transformer and of which the cross-section is constant along the axis (z) of the transformer.The transformer receives from the gyrotron cavity a complex mode, of TE.sub.on type, and changes said mode into a mode in which the electrical field is approximately parallel to a given direction (z). A system of two mirrors (M.sub.3 and M.sub.4) enables a single beam of plane waves (19) to be obtained from the two beams of plane waves (14 and 15) obtained at the output of the section of waveguide (13).

Abstract: A generator is provided based on an interaction of the cyclotronic type between an electron beam propagating between an electron gun and a collector and a high frequency electromagnetic field in a resonating structure. It is principally characterized in that the electron beam moves along a cycloidal path in a transverse magnetic field under the effect of a drift velocity created by a continuous electric field.

Abstract: An electron beam device which includes a vacuum enclosure which houses an electron gun for producing an annular beam of helically rotating electrons, an iris-loaded waveguide which is supplied with high frequency power and serves to create a high frequency electromagnetic field along the axis of the beam which has a longitudinal electric field component along the beam axis, and a resonator which abstracts high frequency energy from the beam. A coil surrounds the vacuum enclosure to provide a magnetic field of increasing strength with distance downstream in the region of the iris-loaded waveguards whereby the angular velocity of the electrons in the beam is increased with little change in the axial velocity.

Abstract: A device is provided for injecting an electron beam propagating along an axis (x) in a cycloidal path under the action of a continuous electric field and a static magnetic field (B) perpendicular to the axis of propagation and to the electric field. The injection device comprises an electron gun placed in a weak magnetic field (B.sub.1) and means, placed in a magnetic field (B.sub.2) increasing progressively along the axis (x), for creating in this zone a continuous electric field having two components in the plane perpendicular to the magnetic field.

Abstract: An electron gun of the type comprising two electrodes facing each other and brought to different potentials so as to create therebetween a continuous electric field and a cathode positioned in the extension of the electrode at negative or zero potential and brought to the same potential as this latter, the assembly being subjected to a magnetic field perpendicular to the electric field. In the plane perpendicular to the magnetic field, at least one of said electrodes has a divergent profile so that the distance between electrodes increases from the cathode towards the outside of the gun.

Abstract: This invention concerns a microwave generator. For the purpose of maintaining synchronism between the microwave and electrons, at high energy levels (e.g. 0.5 to 1 MeV), the first part of the generator comprises a cylindrical wave guide, the section of which increases in radius along the direction of propagation of the electron beam. Such generators can be used to obtain millimeter and submillimeter waves, with high transverse evergy (e.g. approximately 10 MeV).

Abstract: A device having means for forming a high frequency excitation zone in an elongated enclosure, a vacuum pump whose connection is positioned at one end of the enclosure, a device permitting the injection into the enclosure of a gaseous mixture containing at least one compound of the substance to be deposited in the vicinity of but outside the excitation zone. The solid on which the deposit is to be made is positioned in the enclosure. The deposition area on said solid is limited to an area of the enclosure outside the high frequency excitation zone in which the gaseous mixture is almost completely decomposed by high energy particles emitted in said zone.

Abstract: An electron beam transmitted in the direction of an axis XX is subject to the action of a magnetic field, which is constant in time and directed along the axis XX, as well as to the electromagnetic field of resonant cavities placed along its path. These cavities are excited at the cyclotron frequency of the electrons in the field by a source coupled by an antenna. Output power, at a frequency which is near a multiple of the cyclotron frequency, is collected by a second antenna and coupled to a load. In one example, the cavities comprise a single guide, whose circular cross-section has been deformed so as to provide two extensions.

Abstract: A high power hyperfrequency emission tube which comprises, in a vacuum envelope:means for generating and focussing an electron beam;a plurality of energy collecting means;a plurality of means for accelerating the electrons of the beam, formed by hyperfrequency circuits.The collecting means and the accelerating means are distributed along the path of the electron beam and in its direction of propagation, with a spatial period D.sub.c and D.sub.a which is inherent in them, the accelerating means restoring to the electron beam the energy lost at the level of the collecting means.

Abstract: An electrical machine operating at radio frequencies, which comprises a stator S and a rotor R displacing in relation to the latter, for example in a rotational motion. The rotor comprises oscillatory circuits at the rate of one per pole. In a variant embodiment, the stator is designed as a low-pass filter made up of inductors in series between two conductors, capacitors and a common conductor. Commencing from a certain rotational speed on the part of the rotor which is driven by a motor, power amplification takes place between the input and the output of the filter.

Abstract: An ion source supplying a dense flux of low energy ions containing very few neutral particles. It comprises: a microwave circuit in which an electromagnetic wave propagates along a direction ZZ, the conducting elements forming this circuit being arranged periodically and being ring-shaped, inlet means for a neutral gas at the center of the microwave circuit, this gas being ionized thanks to the energy supplied to it by the microwave, a magnetic field guiding the resulting plasma in the direction ZZ, and means for pumping the unionized atoms in a direction normal to the direction ZZ, all along the microwave circuit.