CN210110700U

CN210110700U - Controllable array type field emission X-ray source device

Info

Publication number: CN210110700U
Application number: CN201921457293.0U
Authority: CN
Inventors: 吴大军; 陈玉尧; 张向; 张磊; 钱斌
Original assignee: Changshu Institute of Technology
Current assignee: Changshu Institute of Technology
Priority date: 2019-09-04
Filing date: 2019-09-04
Publication date: 2020-02-21
Anticipated expiration: 2029-09-04

Abstract

The utility model discloses a controllable array field emission X ray source device, including encapsulating at inside field emission electron source part of shell, X ray source part and at the outside measurement system of shell. The field emission electron source part comprises an array cathode, a PCB board carrying an IC chip for controlling the electron emission density and area of the array cathode, and a mesh grid. The front surface of the PCB is provided with a plurality of metal salient points, and the array cathode is arranged at the rear part of the mesh grid and is connected with a PCB circuit through the metal salient points. The metal convex points are connected with the array cathodes, so that the heat dissipation area of the array cathodes is increased, the heat dissipation efficiency is improved, and the stability of the field emission electron source is ensured.

Description

Controllable array type field emission X-ray source device

Technical Field

The utility model relates to a field emission device field especially relates to a controllable array field emission X ray source device.

Background

The field emission has many advantages such as low operation temperature, no time delay, and low power consumption, so that it is a very effective electron emission method, and in recent years, the research on theory and technology is more and more intensive, and the application field is more and more extensive. Therefore, the X-ray source developed by the field emission cathode has the advantages of controllable emission, zero time response and the like. The field emission requires larger electric field intensity to inhibit the surface potential barrier of the cathode, which requires a driving power supply to have higher output voltage on one hand, and on the other hand, with the development of CT, the programmable emission of the X-ray source on time and space is realized, and a multi-point emission X-ray source array is formed. At present, the heat dissipation performance of a field emission device is poor, and the probability of thermal breakdown under high current density is high, so that the stability of a field emission electron source is poor.

Disclosure of Invention

The purpose of the invention is as follows: aiming at the prior art, the controllable array type field emission X-ray source device is provided, so that the heat dissipation efficiency of the device is improved, and the stability of a field emission electron source is ensured.

The technical scheme is as follows: a controllable array type field emission X-ray source device comprises a field emission electron source part, an X-ray source part and a measuring system, wherein the field emission electron source part and the X-ray source part are packaged in a shell;

the field emission electron source part comprises an array cathode, a PCB board loaded with an IC chip for controlling the density and the area of emitted electrons of the array cathode, and a mesh grid; the IC chip is arranged on the back of the PCB and is connected with a computer through a data line; the front surface of the PCB is provided with a plurality of metal salient points, the array cathode is arranged behind the mesh grid and is connected with a PCB circuit through the metal salient points, and the mesh grid is connected with a ground wire;

the X-ray part comprises a copper target, a beryllium window and a high-voltage power supply, the copper target and the beryllium window are fixed on the shell, and the copper target is connected with the high-voltage power supply;

the measuring system comprises an X-ray detector, an amplifier and an oscilloscope, wherein the X-ray detector is arranged on the outer side of the beryllium window and connected with the amplifier, the amplifier is connected with the oscilloscope, and the oscilloscope is further connected with the computer.

Furthermore, the array cathode is of a porous structure, each hole is correspondingly connected with the metal salient point, and the front end part of the metal salient point is embedded into the hole.

Furthermore, the high-voltage power supply is a controllable power supply with the voltage of 0-50 KV.

Has the advantages that: compared with the prior art that the array cathode is directly connected with the corresponding pin of the PCB circuit, the field emission X-ray source device adopts the metal salient points to connect the array cathode and the PCB, and is connected with each hole of the latticed array cathode through a hemispherical metal node, so that the field emission X-ray source device plays a role in emitting joule heat while realizing single-hole emission or area emission. The specific principle is that field electron emission is carried out under the conditions of high field intensity and high vacuum, electrons pass through a potential barrier to be emitted through a tunnel effect, escaping electrons bombard an anode to generate ions, the ions and the electrons continuously bombard a cold cathode material, particularly under the condition of large current, the bombardment generates a great amount of joule heat, and the joule heat cannot be dissipated in time to cause thermal breakdown, so that a device fails. The metal convex points of the device are connected with the array cathodes, so that the heat dissipation area of the array cathodes is increased, the heat dissipation efficiency is improved, and the stability of the field emission electron source is ensured.

Drawings

FIG. 1 is a schematic diagram of the structure of the present invention;

FIG. 2 is a cross-sectional view of an array cathode;

fig. 3 is a schematic diagram of a single-pore structure of an array cathode.

Detailed Description

The present invention will be further explained with reference to the accompanying drawings.

As shown in fig. 1, a controllable array type field emission X-ray source apparatus includes a field emission electron source portion enclosed inside a housing 7, an X-ray source portion, and a measurement system outside the housing 7.

The field emission electron source part comprises an array cathode 1, a PCB 3 carrying an IC chip 2 for controlling the electron emission density and area of the array cathode 1, and a mesh grid 4. The IC chip 2 is arranged on the back of the PCB 3 and is connected with the computer 5 through a data line, and the IC chip 2 is also connected with a power supply. The front surface of the PCB is provided with a plurality of metal salient points 6, the array cathode 1 is arranged at the rear part of the mesh grid 4 and is connected with a circuit on the PCB through the metal salient points 6, and the mesh grid 4 is connected with a ground wire.

The X-ray part comprises a copper target 8, a beryllium window 9 and a high-voltage power supply, wherein the copper target 8 and the beryllium window 9 are fixed on the shell 7, and the copper target 8 is connected with the high-voltage power supply. The voltage power supply is a controllable power supply with the voltage of 0-50 KV.

The measuring system comprises an X-ray detector 10, an amplifier 11 and an oscilloscope 12, wherein the X-ray detector 10 is arranged on the outer side of the beryllium window 9 and is connected with the amplifier 11, the amplifier 11 is connected with the oscilloscope 12, and the oscilloscope 12 is further connected with the computer 5.

In the embodiment, a constant Bo high voltage HB-Z103 type is selected as a high voltage power supply, a self-made silicon micro-channel plate base device Si-MCP is adopted as an array cathode 1, an association E470 is adopted as a computer, a pioneer science and technology HR-25-X-Ray and PA-210/230 type front-end amplifier is selected as an X-Ray detector, and Agilent 86100A is selected as an oscilloscope; both the IC chip and the PCB are available in the prior art, can be purchased from the market, and can be used for circuit design and connection according to corresponding product manuals.

The metal salient points 6 of the device are connected with the array cathode 1, as shown in fig. 2 and fig. 3, the array cathode 1 is a porous structure, the whole height of the array cathode 1 is 200 micrometers, a single hole is a square with the length of 10 micrometers, the thickness of the hole wall is 3 micrometers, each hole is connected with the metal salient points 6, and particularly, the front end parts of the metal salient points 6 are embedded into each hole of the array cathode 1. The metal salient points are connected with the array cathode and the PCB, so that the heat dissipation area of the array cathode is increased, the effect of dissipating Joule heat is achieved while single-hole emission or area emission is achieved, the heat dissipation efficiency is improved, and the stability of the field emission electron source is ensured.

The utility model discloses a field emission X ray source device, the operation is convenient with the maintenance, and the technical staff can control the launching point of array formula negative pole through the computer to the region and the intensity of control electron source transmission realize the multiple spot electron emission, thereby obtain many beam X ray sources.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. A controllable array type field emission X-ray source device is characterized by comprising a field emission electron source part, an X-ray source part and a measuring system, wherein the field emission electron source part and the X-ray source part are packaged in a shell;

2. The device of claim 1, wherein the array cathode is a porous structure, each hole is connected to the metal bump, and the front end of the metal bump is inserted into the hole.

3. The device of claim 1, wherein the high voltage power source is a controllable power source with a voltage of 0-50 KV.