Abstract: A plasma thruster includes extraction of a stream of positive ions. The plasma thruster includes a single ionization stage; injecting ionizable gas for said ionization stage comprising injecting a first gas and an electronegative second gas; creating an RF electric field to cause the gases to ionize in the ionization stage creating a first zone called the hot zone, in the ionization stage; the first gas being distributed in the hot first zone, the second gas being distributed in a second zone less hot than said first zone; extracting a stream of negative ions and a stream of positive ions, these being both connected to the ionization stage; and the extraction of a stream of positive ions and the extraction of a stream of negative ions, ensuring that the thruster is electrically neutral.

Abstract: A plasma motor for extracting a positive ion flow has a single ionization stage and a device for supplying the ionization stage with an ionizable electronegative gas. The plasma motor further has a device for creating an electric field so as to produce the ionization of the gas in the ionization stage. The device for creating the electric filed includes a device for extracting a negative ion flow and, a device for extracting a positive ion flow, connected to the ionization stage. The extraction of a positive ion flow and the extraction of a negative ion flow are of the same amplitude, ensuring the electrical neutrality of the motor. The extraction of a positive ion flow and the extraction of a negative ion flow allow the neutrality of the motor to be ensured.

Abstract: The invention relates to a method and device for forming a plasma beam. According to the invention: the quality of the electroneutrality of the plasma beam (PB) is detected (in 12 and/or 13); and the alternating polarization potentials of the extraction and acceleration grid (4) are adjusted such that the plasma beam (PB) is at least approximately electrically neutral.

Abstract: The invention relates to a method and device for forming a plasma beam. According to the invention: the quality of the electroneutrality of the plasma beam (PB) is detected (in 12 and/or 13); and the alternating polarisation potentials of the extraction and acceleration grid (4) are adjusted such that the plasma beam (PB) is at least approximately electrically neutral.

Abstract: A plasma thruster includes extraction of a stream of positive ions. The plasma thruster includes a single ionization stage; means for injecting ionizable gas for said ionization stage, said means comprising at least first means for injecting a first gas and second means for injecting an electronegative second gas; means for creating an RF electric field so as to cause the gases to ionize in the ionization stage, said means creating a first zone called the hot zone, in the ionization stage; the first gas being distributed in the hot first zone, the second gas being distributed in a second zone less hot than said first zone; first means for extracting a stream of negative ions and second means for extracting a stream of positive ions, these being both connected to the ionization stage; and the extraction of a stream of positive ions and the extraction of a stream of negative ions, ensuring that the thruster is electrically neutral.

Abstract: The subject of the invention is a plasma motor for the extraction of a positive ion flow. The plasma motor has a single ionization stage (1) and means (6) of supplying said ionization stage with an ionizable electronegative gas. Means are provided for creating an electric field so as to produce the ionization of the gas in the ionization stage; First means for extracting a negative ion flow are provided and, second means are provided for extracting a positive ion flow, connected to the ionization stage. The extraction of a positive ion flow and the extraction of a negative ion flow are of the same amplitude, ensuring the electrical neutrality of the motor. According to the invention, the extraction of a positive ion flow and the extraction of a negative ion flow allow the neutrality of the motor to be ensured without recourse to a neutralizer as in the prior art. The application is useful for propulsion of spacecraft in space.