Multistage Focusing Cathode Electron Gun for Extremely Microfocus X-ray Tubes

Abstract

The invention discloses a multi-stage focusing cathode electron gun for an extremely micro-focus X-ray tube, which includes a stem, a heater, a heater support seat, a first-level grid, a second-level grid and a third-level grid, wherein , the stem is provided with a number of electrodes, part of the electrodes on the stem are connected to the heater supporting seat, the heater is installed on the heater support, and the heater is connected to the heater The electrode on the stem is connected, the first level grid is connected with the heat element support base, the second level grid is connected with the first level grid, and the third level grid is connected with the second level grid. grid connection. The heat of the above-mentioned multi-level focused cathode electron gun lights up and emits electrons. The first level grid applies negative voltage to gather electrons, the second level grid adds 1500V high voltage to accelerate electrons and control the tube flow, the third level grid gathers electron flow and Under the action of a high-voltage electric field, the hot electron flow can reach a focal point of 5 μm at a distance of 18 mm, making it possible to use an X-ray tube with a 5 μm focus and a tube voltage of 100KV.

Description

Technical field [0001] The invention relates to an electron gun, in particular to a multi-stage focusing cathode electron gun for a very micro-focus X-ray tube. Background technique [0002] At present, the domestically produced X-ray tubes are all large-focus X-ray tubes with a minimum focus of 0.3mm×0.3mm; they are commonly used in medical and health, high-power process inspection, security inspection and other fields. With the continuous development of the field of technology, surface mount (SMT) technology has emerged. Using SMT technology can reduce the volume of electronic products by 40-60% and weight by 60-80%. But what follows is the traditional inspection methods. Ordinary focus X-ray machines can no longer meet the quality and reliability requirements of existing production products, especially the internal defects of the components. In this way, a new detection method appeared, the micro-focus X-ray machine. The core device of this equipment is the micro-focus X-ray...

AI Technical Summary

Problems solved by technology

But what followed was the traditional detection methods, such as ordinary focus X-ray machines, etc. can no longer meet the quality and reliability requirements of existing production products, especially for internal defects of components cannot be identified

In this way, a new detection method has appeared, the micro-focus X-ray machine. The core device of this equipment is a micro-focus X-ray tube. If you want to make an X-ray tube with a small focus, you must have an extremely fine electron flow. At present, there is no X-ray tube with a focus of less than 300 μm in China.

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