Abstract

An X-ray tube is described having a filament for generating electrons (5), a cathode, and an anode (8) which comprises an elongate member (17) having a fixed point relative to the sealed housing of the tube and an end that is moveable relative to the sealed housing. The longitudinal axis of the elongate member in a rest position is laterally displaced relative to the path of the accelerating electrons, whereby a spherical target surface on the moveable end of the member may be moved relative to the impinging electrons such that the spatial location of X-ray generation in the tube is invariant relative to the sealed housing, thereby spreading localised heating caused by the X-ray generation over a greater portion of the target surface. The member is typically driven such that the anode precesses about the X-ray beam.

IPC Classes  ?

• H01J 35/28 - Tubes wherein the point of impact of the cathode ray on the anode or anticathode is movable relative to the surface thereof by vibration, oscillation, reciprocation, or swash-plate motion of the anode or anticathode