Emi, LLC

Robert Paul Randall

Christopher Archibald LeMay

An X-ray tube is described in which, in order to produce a well defined electron beam which can be accurately focussed on the target of the tube, the cathode comprises a flat plate member, such as a tape or foil, the surface finish of which is sufficiently smooth that electrons are emitted therefrom with lateral energies below 0.2 electron volts. The aforementioned surface finish is such that irregularities in the electron-emitting surface of the cathode do not exceed one micron in amplitude.

X-ray tubes

In an X-ray tube arrangement of the kind in which an electron beam is deflected along a target/anode there is provided means for monitoring the progress of the deflection to correct for errors. Detectors are provided to receive radiation from the regions of intended reversals in the scan. By monitoring maxima and minima in the waveform from those detectors the true position of the reversals can be estimated.

X-ray tube arrangement

Radiographic apparatus is described in which an X-ray tube incorporates a cathode which is heavily driven to produce a strong electron beam. In order to minimize the demands placed on the cathode, the X-radiation emitted by the tube (or the electron beam produced by the cathode and causing the emission of the X-radiation) is monitored and used to control the supply of energy (e.g. heater current) to the cathode.

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Uxbridge, United Kingdom

Robert Paul Randall