Cold-cathode focusing type X ray tube

Abstract

The invention relates to a cold cathode focused X-ray tube, wherein, the tube comprises a cold cathode electron source (14), a focused electrode (7), a vacuum sealed shell body (9), a ray emission window (10), a high-voltage anode target (11) and the like, and is characterized in that the tube also comprises a zinc oxide emission layer (5) attached to the cold cathode electron source (14). In the invention, based on a plane grid electrode structure, the electron source is prepared on the surface of a glass substrate (6) in a silk screen printing manner; the high-voltage anode target (11) is fixed right above the electron source; the electrode is arranged in a ceramic vacuum shell body and connected with an external power supply by electrode leads. The ceramic shell body adopts a segmented sealing method; and a metal focused electrode (7) is arranged above the cold cathode electron source (14), and insulation and sealing with ceramics are carried out to the focused electrodes. The focused electrodes can greatly condense electron beams bombarded on the surface of the anode target so as to realize X-ray emission with high resolution factor.

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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