Vacuum diode with high current, small focal spot and long service life

Abstract

The invention relates to a vacuum diode with high current, small focal spot and long service life. The original diode in a repetition frequency fast-pulse hard X-ray generator is modified, the structure and the material of movable cathode and anode assemblies are improved, a cathode head is made of tungsten nickel copper alloy materials and is seated on a movable support, a conical hole structure inwards forming a sharp end bulge is used for emitting electrons and is aligned with X rays, and an anode target is made of metal tantalum materials and is fixedly arranged on a copper core wire through screw threads. The conical annular cathode structure is improved, the radius of sent plasmas is favorably controlled, dense plasmas can be conveniently obtained, the self pinching condition in the electronic beam transporting process is met, submillimeter beam spots are formed, and the detailed imaging requirement of the pulse imaging field is met.

Description

technical field [0001] The invention is an electron beam diode invented on the basis of a repetition frequency pulse power supply, which is used to generate high-current small focal spot pulse hard X-rays, and belongs to the application field of pulse power technology. Background technique [0002] In recent years, small focal spot pulsed radiation imaging technology has gradually become a development trend in the field of radiation imaging due to its characteristics of strong transient radiation, short irradiation time, less interference from environmental radiation during the imaging process, and controllable dose of irradiated objects. Compared with the current steady-state X-ray machine widely used in the field of radiation imaging (the current technical index is generally 50μA ~ 100mA), it has outstanding advantages in the following fields: [0003] (1) It can play a unique role in the fields of military, anti-terrorism and national defense industries, including detecti...

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Problems solved by technology

[0007] 1) Its transmission type target structure composed of anode film, supporting disk and vacuum sealing film is difficult to achieve long life and high power density operation;

[0008] 2) The structure of the cathode and anode assembly does not meet the pinch condition, and its X-ray beam is emitted at 4π, which cannot meet the requirements of refined imaging;

[0009] 3) The two ends of the bellows are connected by crimping. When adjusting the distance between the anode target and the cathode target, it is difficult to maintain the vacuum for a long time, making it unsuitable for pulse imaging.

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