Abstract: The invention, which relates to a miniaturizable plasma thruster, consists of: —igniting the plasma by microhollow cathode discharge close to the outlet and inside the means for injecting the propellant gas, said injection means being magnetic and comprising a tip at the downstream end thereof; —bringing the electrons of the magnetized plasma into gyromagnetic rotation, at the outlet end of said injection means; —sustaining the plasma by means of Electron Cyclotron Resonance (ECR), said injection means being metal and being used as an antenna for electromagnetic (EM) emission, the volume of ECR plasma at the outlet of said injection means being used as a resonant cavity of the EM wave; —accelerating the plasma in a magnetic nozzle by diamagnetic force, the ejected plasma being electrically neutral.

Abstract: The invention, which relates to a miniaturisable plasma thruster, consists of: —igniting the plasma by microhollow cathode discharge close to the outlet and inside the means for injecting the propellant gas, said injection means being magnetic and comprising a tip at the downstream end thereof; —bringing the electrons of the magnetised plasma into gyromagnetic rotation, at the outlet end of said injection means; —sustaining the plasma by means of Electron Cyclotron Resonance (ECR), said injection means being metal and being used as an antenna for electromagnetic (EM) emission, the volume of ECR plasma at the outlet of said injection means being used as a resonant cavity of the EM wave; —accelerating the plasma in a magnetic nozzle by diamagnetic force, the ejected plasma being electrically neutral.

Abstract: A thruster (1) has a main chamber (6) defined within a tube (2). The tube has a longitudinal axis which defines an axis (4) of thrust; an injector (8) injects ionizable gas within the tube, at one end of the main chamber. An ionizer (124) is adapted to ionize the injected gas within the main chamber (6). A first magnetic field generator (12, 14) and an electromagnetic field generator (18) are adapted to generate a magnetized ponderomotive accelerating field downstream of said ionizer (124) along the direction of thrust on said axis (4), The thruster (1) ionizes the gas, and subsequently accelerates both electrons and ions by the magnetized ponderomotive force.

Abstract: A frame is placed in the flow of incident air from a laminar flow hood, and bare wires and insulated wires are stretched over the frame. A source including a transformer produces an alternating voltage. One of the outputs thereof is directly connected to the insulating wires and the other output thereof is connected to the bare wires via a capacitor. An electrode placed inside the volume of the cabinet fed with air from the hood is connected to a DC amplifier which applies a correcting voltage to the insulated wires. This apparatus turns out to be highly effective, in particular, for removing dust and neutralizing charge when manufacturing VLSI circuits.

Abstract: A gas carrying solid particles is purified by electrically charging the sd particles and precipitating them by electrostatic means. The particles carrying gas flows in an enclosure wherein a space charge is formed by ion generators. Each ion generator comprises an injector tube which defines a chamber communicating with the enclosure via a small opening. Moist air is fed under pressure in the chamber and is accelerated in a tuyere in this opening. A corona discharge is formed at the neck of the tuyere by applying a high voltage between the tuyere and a coaxially arranged needle like electrode. Microparticles of ice are formed in the corona discharge zone by reason of the supersonic gas discharge in the tuyere. Ions trapped by these microparticles are driven out of the ion generators chamber into the enclosure wherein the gas stream to purify flows. These ions are freed by evaporation of the ice microparticles to form the space charge.

Abstract: The invention relates to a method and to a structural element for protecting an aircraft against the building-up, when flying, of electrostatic charges on the external metallic surface of the aircraft normally coated with a finishing dielectric paint.The structural element of the aircraft is subjected to a treatment consisting in applying on the external metallic surface of the aircraft, prior to the depositing of the finishing paint, a resistive electrostatic protection layer having a surface resistivity of between 1 and 100 M.OMEGA. per square and being connected to the reference electric potential (i.e., ground or mass) of the frame or body of the aircraft.The the protective layer is provided, for example, by applying at least a paint layer forming, once dry, a coating exhibiting the required surface resistivity.

Abstract: A flash-spark creeps on a dielectric surface to ignite carburated gaseous xtures. A high voltage pulse is applied through the dielectric between opposite surfaces thereof. The voltage is applied between a first electrode having a smaller area abutting against a first surface of the dielectric and a second electrode having a first strip portion abutting against an opposite second surface of the dielectric and a second portion which is astride an edge of the dielectric. The strip portion ends at a position beneath the first electrode. The first surface is exposed to the carburated gaseous mixture.

Abstract: A gas carrying solid particles is purified by electrically charging the solid particles and precipitating them by electrostatic means. The particles carrying gas flows in an enclosure wherein a space charge is formed by ion generators. Each ion generator comprises an injector tube which defines a chamber communicating with the enclosure via a small opening. Moist air is fed under pressure in the chamber and is accelerated in a tuyere in this opening. A corona discharge is formed at the neck of the tuyere by applying a high voltage between the tuyere and a coaxially arranged needle like electrode. Microparticles of ice are formed in the corona discharge zone by reason of the supersonic gas discharge in the tuyere. Ions trapped by these microparticles are driven out of the ion generators chamber into the enclosure wherein the gas stream to purify flows. These ions are freed by evaporation of the ice microparticles to form the space charge.

Abstract: In a supersonic nozzle, a current of compressed air charged with humidity is expanded to produce an aerosol of ice micro-particles. A corona discharge is maintained at the neck of the nozzle at the tip of a tapered electrode by a high alternating current voltage supply connected between the electrode and the nozzle body. The alternately positive and negative ions produced by the discharge are trapped by the ice micro-particles and ejected by an orifice at the front of the nozzle out of the enclosure in the direction of a space zone the concentration in charges of different signs of which it is desired to raise. The electric supply comprises a capacitor in the circuit between the electrode and a conductive guard ring which is embedded in the body of the nozzle behind the insulating surface thereof. Thus fluxes of positive and negative particles which are overall balanced are obtained at the exit of the nozzle. The apparatus is well adapted to the elimination of static charges of electrified bodies.

Abstract: A device for producing a gaseous stream carrying electric charges, particrly in view of influencing the electric voltage of a body, particularly of an airship such as a helicopter, comprising a metallic needle connected to a first pole of a high voltage electric source and having a point which is arranged in the neck of a metallic nozzle supplied with a source of compressed air to create a stream carrying the electric charges, the nozzle being arranged at one end of an electrically insulating hollow duct means for ejecting the stream towards the atmosphere, the ejection opening of the stream being surrounded by a massive hood made of an electrically insulating material.