Cathode of cold-cathode X-ray tube

Abstract

The invention provides a cathode of a cold-cathode X-ray tube. The cathode of the cold-cathode X-ray tube comprises a cathode base and a grid electrode, wherein the cathode base is composed of an upper cylinder and a lower cylinder which are coaxially arranged, the section of the cathode base is in an inverted-T shape, a cathode bar through hole is formed in the central axis of the cathode base, a cathode bar is arranged in the through hole, the three-dimensional size of the cathode bar can be controlled, an electron emitter is arranged on a cathode head, the grid electrode is of an cup-shaped structure, an inverted-T-shaped groove which is matched with the cathode base is formed inside the grid electrode, the cathode base can be embedded in the groove of the grid electrode and does not make contact with the inner wall of the grid electrode, and a semi-conical electron transmission hole used for focusing electrons emitted by the cathode is formed in the center of the grid electrode. According to the cathode of the cold-cathode X-ray tube, the cold cathode made of carbon nanomaterials is used as the X-ray tube of an electron emission source, and preparation of the cathode and the emission area can be effectively controlled through the size of the cathode bar; the three-pole structure is adopted, a small focus point can be obtained through focusing of the grid electrode, and the resolution ratio of X-ray imaging is increased.

Description

Technical field [0001] The invention relates to an X-ray tube, in particular to a cold cathode X-ray tube cathode. Background technique [0002] X-ray tube is a device that realizes controllable emission of X-rays. They are used in various systems, such as X-ray imaging technology, spectral analysis (X-ray fluorescence spectroscopy, X-ray photoelectron spectroscopy), X-ray diffraction analysis, etc. in medical, industrial, and security fields. The principle of generating X-rays in an X-ray tube is to use high-energy electrons (tens of thousands of electron volts) to bombard a metal target. The interaction between these electrons and the target material is multiplied until X-rays are emitted. X-ray intensity is directly proportional to the electron flow reaching the target material. The penetration of X-rays is directly proportional to the applied voltage on the target material. The emission area of ​​X-rays is determined by the range of the electron beam bombarding the ta...

AI Technical Summary

Problems solved by technology

However, hot cathodes have defects such as large volume, long electron emission modulation time (millisecond level), and high power consumption.

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