Abstract: The invention relates to an electrical machine. The stator 1 is a delay line, in the form of a low-pass filter in the example, formed by inductance 11 and capacitors 12 connected between these inductances and the common conductor 13. The rotor 2 comprises dissipating elements 22 incorporated in circuits 26, separate in the example, and having a common point 25. It is put in movement by a motor. The machine operates as a high-gain amplifier having a wide band of high-frequency signals applied to the input 14 of the stator, separated from the output 15 by the decoupling zone 30. High powers are obtainable.Application to installations for testing vibration of industrial equipment and to high-power longwave radio transmission.

Abstract: This invention deals with a process of separating isotopes. Isotopes of atomic mass m.sub.1 and m.sub.2 are in a plasma. Isotope m.sub.1 is of low concentration and isotope m.sub.2 is dominant. The plasma is submitted to a time constant uniform magnetic field and to an orthogonal high frequency electric field. To facilitate the separation a third isotope of atomic mass m.sub.3 is included in the plasma. The atomic mass m.sub.3 of the third isotope is such that m.sub.3 =2m.sub.1 -m.sub.2 and its concentration is (for all practical purposes) equal to that of the dominant isotope. The frequency of the electric field is adjusted to the value of the cyclotron frequency of the isotope of mass m.sub.1 in the plasma. One thus compensates the polarization of the plasma due to the dominant isotope and increases the tolerance of the process to the natural fluctuations of the plasma.

Abstract: In a rotary electrical machine, in order to achieve an amplification effect with a high output level, the windings of a series of stators, aligned in front of a series of rotors, assembled upon one and the same axle, are connected to a common (earth) conductor across capacitors. In this fashion a filter made up of .pi.-cells is obtained, whose amplification factor vis-a-vis a signal injected at the input of the machine, between earth and a terminal, is given by: ##EQU1## THIS FOR A MACHINE COMPRISING N rotors and N stators between said input and output, at which the amplified signal is picked off. L.sub.s designates the self-inductance of a stator, C the capacitance of the capacitors, and R the negative resistance which appears in operation within the winding of said stator.

Abstract: An electronic tube of magnetron type capable of operating as a self excited oscillator or an amplifier pilot- controlled to a given frequency. It comprises a waveguide surrounding the anode of the magnetron. The waveguide which comprises an output and an input is coupled at coupling points to certain cavities of the magnetron. The waveguide is formed by successive sections each extending from one of the coupling points to the next and each having a constant characteristic impedance. The guide offers to the wave a characteristic impedance which varies regularly from one of its section to the other. When operating as a self excited oscillator the input at the opposite end to the output is closed off.

Abstract: A millimetric wave tube for generating high energy pulses, comprising, in particular, a slotted cylindrical anode carrying resonant cavities, and means for creating an electron cloud rotating about the axis of the anode, and performing the function of a negative electrode. An energy exchange takes place from the electron cloud to a millimetric wave which develops in the resonant cavities, so that the millimetric wave is amplified.

Abstract: The ion source according to the invention comprises a hollow cathode discharge arrangement 10 in which a plasma is produced by the ionization of a gas under the effect of a positive d.c. voltage applied to an anode 3 in relation to two cathodes 1 and 20. One of these cathodes 20 is formed with holes 30 through which some of the ions of the plasma escape. A filament 7 emits slow electrons towards this cathode, neutralizing the space charge created ahead of this cathode by the ions having left the arrangement and enables them to be propagated towards a point of use 40 situated at a considerable distance. A grid 8 limits the number of these electrons entering the arrangement 10. The source provides ion beams of clearly defined energy and high density.

Abstract: A device for providing a tunable impedance due to variations of a multipactor discharge; the device of the invention gives rise to low insertion losses when incorporated in another device, due to particular structure provides a longitudinal drift of the electrons of the discharge which thus have an elongated trajectory before stricking an electrode.

Abstract: This device essentially comprises a resistive element connected between two conductor elements one of which is attached to one of the two walls between which the waves requiring attenuation appear, and the other of which is located opposite the other wall, constituting a capacitor in relation thereto; such devices are disposed in regions of high frequency tubes such as magnetrons or tetrodes devoided of useful waves.

Abstract: The device in accordance with the invention comprises a conductor ring disposed coaxially to the two electrodes in such a fashion that the parasitic waves develop surface currents there, n absorptive elements distributed around said ring being provided in order to attenuate said surface currents; this device is applicable in particular to magnetrons or to tetrodes with cylindrical electrodes.

Abstract: A device for attenuating very short parasitic waves which create surface currents at the surface of a conductive wall of a high frequency circuit, said device comprising within an opening provided in the wall, a highly resistive element exhibiting magnetic losses; the surface currents which form a loop around said element, generate therethrough an alternating magnetic field providing magnetic losses which attenuate said parasitic waves.

Abstract: Cavity resonator electronic tubes, in particular magnetrons, with an electronic tuning system. The tuning systems in accordance with the invention consist of multipactor elements arranged directly within the resonant volumes of the tube cavities. Frequency tuning can be effected either by switching between two predetermined frequencies or by continuous change of the frequency.