A miniaturized non-radioactive electron source with controllable emission current

Abstract

The invention relates to the technical field of vacuum electronics, and provides a miniaturized non-radioactive electron source with a controllable emission current. The miniaturized non-radioactive electron source mainly comprises an acceleration voltage source, an ampere meter, an extraction voltage source, a filament heating current source, filaments, an extraction grid, an acceleration electrode, a silicon nitride film and a vacuum cavity, wherein the extraction grid is positioned in a position in front of the filaments, having a distance of 1mm from the filaments, in the vacuum cavity; the acceleration electrode is arranged at the other end of the vacuum cavity; the silicon nitride film is attached to a central opening of the acceleration electrode outside the vacuum cavity; by virtue of the acceleration voltage source, electrons emitted from the filaments are accelerated to obtain kinetic energy; by adjusting the extraction voltage source, focusing or defocusing of the electron beams in the vacuum cavity can be controlled; the space between the extraction grid and the acceleration electrode is an acceleration region with a length of 5mm; the current can reach 0-300mA when the filaments are in use; an electron extraction electric field between the filaments and the extraction grid is independent from an acceleration electric field, so that electron emission can be controlled by adjusting the current of the filaments and the extraction electric field; and the silicon nitride film is 1*1mm<2> in area and 250nm in thickness.

Description

technical field [0001] The invention relates to the technical field of vacuum electronics, in particular to a miniaturized non-radioactive electron source with simple design and effective operation with controllable emission current. Background technique [0002] The disadvantages of the commonly used radioactive β-decay electron sources are: the ionization parameters cannot be changed, such as ionization time, electron kinetic energy, electron current, density, etc., and in many applications, the use of radioactive sources is not allowed. Especially in terms of electron focusing, the disadvantages of existing non-radioactive electron sources are: complex structure, excessive volume of electron focusing system, including an electrostatic lens system and a magnetic electron beam guiding device, both of which require a considerable vacuum cavities, and electrostatic lens systems operate at high potentials, requiring sophisticated electronics. In addition, some existing non-ra...

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Problems solved by technology

[0002] The disadvantages of the commonly used radioactive β-decay electron sources are: the ionization parameters cannot be changed, such as ionization time, electron kinetic energy, electron current, density, etc., and in many applications, the use of radioactive sources is not allowed. Especially in terms of electron focusing, the disadvantages of existing non-radioactive electron sources are: complex structure, excessive volume of electron focusing system, including an electrostatic lens system and a magnetic electron beam guiding device, both of which require a considerable vacuum cavity, in addition, the electrostatic lens system operates at high potentials and requires complex electronics

In addition, some existing non-radioactive electron sources cannot achieve the same performance as radioactive electron sources, especially the kinetic energy of the emitted electrons is small

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