The ion source comprises a primary plasma generator constituted by a hot cathode and an anode, between which an arc is produced, and by an intermediate electrode enclosing the arc in proximity to an extraction orifice pierced in the anode. Magnetic field creating means are provided between the intermediate electrode and the extraction orifice, which has a relative small cross-section so that the pressure of the gases occurring inside the primary plasma generator is independent of the pressure existing downstream of the extraction orifice. This pressure downstream of extraction orifice is less than the pressure inside the primary plasma generator. On the downstream side there is an extraction electrode. A fifth electrode is arranged downstream of the extraction orifice of the anode and upstream of the extraction electrode and means are provided for applying to this fifth electrode a positive potential with respect to that of the anode and of adjustable value, which is small in absolute value with respect to the potential of the extraction electrode.
Methods and apparatus for producing intense megavolt ion beams are disclosed. In one embodiment, a reflex triode-type pulsed ion accelerator is described which produces ion pulses of more than 5 kiloamperes current with a peak energy of 3 MeV. In other embodiments, the device is constructed so as to focus the beam of ions for high concentration and ease of extraction, and magnetic insulation is provided to increase the efficiency of operation.
The first plasma discharge chamber of the dual discharge plasma device contains an electron emitter and a first anode and contains gas at a sufficiently high pressure that the discharge voltage in the first chamber is below the sputtering threshold. The second chamber has a main anode and receives a plume of plasma from the first chamber. The main anode operates at a voltage above the sputtering threshold with a respect to the first anode and the gas in the second chamber is at a low enough pressure for a conventional low pressure plasma discharge which is used as an ion source.
A device and method is disclosed for detecting elemental ions by colliding a beam of the elemental ions with a beam of collision partners having an opposite charge to generate element specific radiation. The radiation whose wavelength is specific to the element is filtered and detected as a measure of the elemental ion. In one case using energy matched collision exchange partners, metal ions of an opposite charge are used as collision partners.
A single-ring magnetic cusp low gas pressure ion source designed for use in a sealed, nonpumped neutron generator utilizes a cathode and an anode, three electrically floating electrodes (a reflector behind the cathode, a heat shield around the anode, and an aperture plate), together with a single ring-cusp magnetic field, to establish and energy-filtering mechanism for producing atomic-hydrogen ions.
An ion source apparatus of surface ionization type comprises an emitter tip in the form of a round rod having a sharp-pointed end, an ion source material holder for holding the emitter tip coaxially within a crucible made of a material of a high melting point, the crucible having an opening formed in a bottom wall thereof through which the sharp-pointed end of the emitter tip extends outwardly, the ion source material is being filled in the crucible so as to enclose the outer periphery of the sharp-pointed end of the emitter tip, a filament for emitting electrons with which the emitter tip is bombarded from below, a heating power supply for the filament, an ion beam extracting electrode disposed between the emitter tip and the filament and maintained at a potential of a substantially the level as that of the filament, and an accelerating voltage power supply for applying a high voltage between the ion beam extracting electrode and the emitter tip to accelerate the electrons and ion beam.
