X-rays generator

Abstract

When the focus of an X-ray tube in an X-rays generator is to be made extremely small, a first electrode closest to a cathode out of two or more intermediate electrodes (2b, 2c, 2d) arranged between a cathode (2a) and a target (3) must be brought as close as possible to the cathode, and thereby causing the problem of temperature rise of the first electrode. In the invention, even if the thermal capacity of the first electrode is increased by applying the same potential as that of a container (1) to the first electrode to allow it to touch the container, the function of the X-rays generator is not damaged. Positional relation between an electron gun and the container is determined by allowing the first electrode to touch the container, and assembling work of the X-rays generator is facilitated. Furthermore, management of a power supply is facilitated because the potentials of the cathode, the intermediate electrodes (e.g. the second electrode, the third electrode) and the target are all at positive polarity with respect to the potential of the first electrode.

Description

technical field [0001] The present invention relates to an X-ray generator used in industrial fields, medical fields, and the like. Background technique [0002] X-ray generators (X-ray tubes) are used in industrial fields, medical fields, etc., for example in non-destructive inspection equipment. X-ray tubes mounted on non-destructive testing equipment are broadly classified into open type X-ray tubes and closed type X-ray tubes. In the case of an open type X-ray tube, the container is evacuated by a turbomolecular pump or the like, and consumables such as a filament and a target forming the cathode can be replaced. In the case of a sealed X-ray tube, a vacuum pump is not required, and the inside of the container is vacuum-sealed. Among them, in the electron gun of the sealed type X-ray tube, from the viewpoint of long-term stability, many planar type cathodes such as those used in cathode ray tubes are mounted as cathodes. [0003] Figure 6 It is a schematic diagram of...

AI Technical Summary

Problems solved by technology

At this time, since the insulator such as alumina bonded to the first electrode 102b generally has poor thermal conductivity, and also has poor heat dissipating ability (radiation) from the thin pillar or strip-shaped electrode 106, the first electrode and its Specified optical dimensions cannot be obtained due to thermal expansion caused by temperature rise of nearby components

In addition, the re-radiation from the first electrode to the cathode increases the temperature of the cathode above the set temperature, causing defects such as life degradation.

[0012] However, even if the heat capacity of each electrode is increased to dissipate heat, as described above, the size of each electrode is limited by the size of the electron gun.

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