Hot-cathode X-ray tube having an end-mounted anode
AssigneeCompagnie Generale de Radiologie
InventorBernard Grubis
Life of this patent
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Abstract
A hot-cathode X-ray tube having an end-mounted anode and a low energy consumption, including a filament, an anode in the form of a plate orientated perpendicularly to the electron beam which is emitted by the filament, an annular auxiliary electrode having a central opening and forming a diaphragm for the electron beam and a secondary anode for back scattered electrons. The anode and the diaphragm are made from the same metal selected from silver, rhodium, copper and molybdenum and at least the portions of the secondary anode facing the primary one are coated with the same metal. The tube may be used as a source of quasi-monochromatic radiation in apparatus for spectrometry by X-ray fluorescence, diffractometry and microradiography.
Claims18
An X-ray tube of the type having a hot cathode at one end, a main anode in the form of a metal plate perpendicular to the axis of the electron beam located at the other end thereof, said beam bombarding the main anode so that at least part of the useful X-ray beam generated by this bombardment passes through the thickness of the main anode, which acts as a filter for the emitted X-ray beam by allowing the characteristic radiation of the material forming the main anode to pass therethrough preferentially, further comprising:
- an annular secondary anode provided with a central opening arranged in the path of the electron beam, near the main anode and coaxial thereto, said secondary anode being at the same electrical potential as the main anode and having at least its surface made of the same metal as the main anode, thereby adding to the characteristic radiation from the main anode, a supplementary characteristic radiation resulting from electrons which are back-scattered due to elastic collisions with the atoms of the main anode and which strike the secondary anode.
Dependencies are inferred from the claim text.