GB1365672A - Hall current accelerators - Google Patents

Abstract

1365672 Ion beam apparatus UNITED KINGDOM ATOMIC ENERGY AUTHORITY 21 Oct 1971 [28 July 1970] 36581/70 Heading H1D A Hall current accelerator comprises an inner core 6a and a co-operating outer annular magnetizable member 6b which together define a passage of annular cross-section, winding means 10 associated with the inner core 6a and energizable to produce a magnetic field directed transversely of the passage, an anode 14 and a cathode 16 arranged at opposite ends of the passage for accelerating ions along the passage, and means for modifiying the magnetic field in the annular passage in such a sense as to cause ions travelling along the passage to be directed substantially parallel to the walls 12 of the core 6a and the member 6b defining the passage. The said means may be a winding 20 (Fig. 2) associated with the outer member, or means for supporting the core 6a and member 6b for relative axial movement, or a backing coil 22 or 24 (Fig. 2). Electrons are trapped and perform orbits in the magnet gaps 8a and 8b whereas ions proceed with a small azimuthal deflection which may be cancelled by an opposite deflection produced by the backing coils 22 and 24. The accelerator may comprise a plurality of magnetic circuits and windings (Fig. 3, not shown) the fields of which decrease in strength in the direction from anode to cathode. The accelerator may be used for vacuum melting or surface coating, or in a plasma wind tunnel (Fig. 4, not shown), or as a neutron source by accelerating deuterium and tritium ions towards a watercooled tritium-loaded target made, e.g. of erbium, or as a pump (Fig. 5, not shown). Gas to be ionized is admitted through a valve arrangement 18. The windings 10 and 20 may be replaced by superconducting coils. in which case an iron core is not necessary. The annular cathode 16 may be replaced by an axially located disc.