A cold cathode focused x-ray tube

Abstract

The invention relates to a cold cathode focusing type X-ray tube. It includes a cold cathode electron source (14), a focusing electrode (7), a vacuum-sealed casing (9), a ray exit window (10) and a high voltage anode target (11). Zinc oxide emissive layer (5) on (14). In the present invention, the electron source is prepared on the surface of the glass substrate (6) by screen printing on the basis of a planar grid structure; the high-voltage anode target (11) is fixed directly above the electron source; the electrodes are placed in a ceramic vacuum shell Among them, it is connected to an external power supply through electrode leads. The ceramic casing is sealed in sections; a metal focusing electrode (7) is placed above the cold cathode electron source (14), and ceramics are also used for insulation and packaging between the focusing electrodes. The electron beam bombarding the surface of the anode target can be greatly compressed by the focusing electrode to realize the emission of high-resolution X-rays.

Description

technical field [0001] The invention relates to an X-ray tube, in particular to a cold cathode focusing type X-ray tube. Background technique [0002] In recent years, X-ray imaging systems have been widely used in medical fields such as diagnosis and treatment, and X-ray tubes, which are the core components of X-ray imaging systems, have also received extensive attention. Traditional X-ray tubes mostly use a filament as the electron source, that is, a hot cathode X-ray tube. By heating the filament, the internal electrons overflow to form effective electron emission. With the development of detection technology and the improvement of detection requirements, hot cathode X-ray tubes can no longer meet the high resolution and real-time requirements of modern X-ray imaging technology due to their inherent shortcomings. On the contrary, field emission cold-cathode X-ray tubes can effectively achieve real-time detection because of their characteristics such as no need for heatin...

AI Technical Summary

Problems solved by technology

However, the further development of this device is limited due to its high working electric field and low working current.

The micromachining mask etching process used in it also increases the complexity of the process and increases the cost.

In addition, if the necessary focusing measures are lacking, the outgoing X-ray beam will have a large divergence angle, which is not conducive to the improvement of the spatial resolution of X-ray imaging.

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