Abstract: A sealed neutron tube is set forth, containing a low-pressure gaseous deuterium-tritium mixture wherefrom an ion source (13) forms an ion beam which traverses an acceleration electrode (17) and is projected with high energy onto a target (16) in order to produce therein a fusion reaction which causes an emission of neutrons. In accordance with the invention, the ion source comprises a cold cathode with strictly electrostatic confinement of ionizing electrons; this is achieved by using an anode which is connected to a positive potential and which has a weakly collective surface facing the repulsive surface of the cathode cavity; the anode is arranged along the axis of the cavity in which it is arranged; said cavity constitutes the internal part of the cathode (15) in which the electrons (e.sub.2) which oscillate along very long paths in comparison with the dimensions of the cathode cavity ionize the gas and form an ionized gas wherefrom the ion beam (22) is extracted for standard ion optical device (17).

Abstract: A device is set forth for the extraction and acceleration of ions in a sealed high-flux neutron tube in which an ion beam (3) is extracted from an ion source (1), after which it is accelerated by means of an acceleration electrode (2) so as to be projected onto a target electrode (4) and produce therein a fusion reaction which causes an emission of neutrons. In accordance with the invention, the device also comprises an extraction-pre-acceleration electrode (13) which is arranged between the ion source and the acceleration electrode and which carries a potential such that the beam extracted from the ion source is initially rendered parallel or slightly diverging in order to obtain a laminated ion beam throughout the zone between the ion source and the target electrode.

Abstract: A device is set forth for the extraction and acceleration of ions in a high flux sealed neutron tube containing a low-pressure gaseous deuterium-tritium mixture, where an ion source (12) supplies several ion beams (3a, 3b, . . . 3e) which are projected onto a target electrode (4) by means of an extraction and acceleration system in order to produce therein a fusion reaction which causes an emission of neutrons.

Abstract: The divergence of the magnetic field for confining the ionized gas (9) in a sealed high-flux neutron tube comprising a Penning-type ion source (1) is increased in the direction of the ion emission zone by influencing the magnet assembly (8) of the ion source. The ion beam extracted from the plasma is accelerated (2) and projected onto a target (4). The geometry and the position of the anode (13) inside the ion source are adapted to the topography of the lines of force in order to ensure minimum interception of the ionizing electrons moving in the structure, which adaptation is achieved notably by using a truncated anode whose generatrices take the shape of the lines of force.

Abstract: A sealed neutron tube is set forth which contains a low-pressure gaseous deuterium-tritium mixture wherefrom an ion source forms an ionized gas which is guided by a magnetic electron confinement field produced by magnets (8), which source emits the ion beams (3) which traversed an extraction-acceleration electrode (2) and which are projected onto a target (4) so as to produce therein a fusion reaction which causes an emission of electrons. In accordance with the invention, the ion source is of a multi-cell type formed by n Penning-type cells comprising a multi-hole anode (6) which is arranged inside the cathode cavity (7) in order to increase the ion current. The shape and/or the dimensions and/or the position of the multi-hole anode are adapted to the topology of the magnetic field.