CN204230202U - A kind of low energy electrons rifle - Google Patents

Abstract

The utility model discloses a low-energy electron gun, which comprises: an electron emission device for emitting electrons; a gate device for accelerating and guiding the electrons and controlling the quantity and speed of the electrons; device; an electron gun shell for accommodating the above-mentioned device in its cavity; and a supporting device for fixing the above-mentioned electron emission device, grid device and focusing device in the cavity of the above-mentioned electron gun shell to act as a fixed support; the focusing device consists of three It is composed of ring electrodes that cooperate with each other; one of the ring electrodes is a positive potential electrode, its front end is insulated from the other two ring electrodes by an insulating ball, and its rear end is also insulated from the grid device by an insulating ball; the remaining two ring electrodes The electrodes cooperate with each other to form an electrode structure, and the electrode structure is at zero potential. The electron gun provided by the utility model has the advantages of low energy, adjustable electron quantity and energy level, compact structure and convenient use.

Description

A low energy electron gun

technical field

The utility model relates to a device capable of emitting low-energy electrons, in particular to a low-energy electron gun.

Background technique

X-ray photoelectron spectroscopy is an electron spectroscopy based on the photoelectric effect. It uses X-ray photons to excite the inner electrons of the surface atoms of the material, and obtains surface composition and electronic state information through energy analysis of these electrons. means. During the X-ray irradiation process, due to the release of a large number of electrons, the substance with relatively poor conductivity is easy to be positively charged, and once the substance is charged, there will be a large deviation or even a wrong conclusion in the analysis of the photoelectron spectrum. Neutralize with electronic compensation.

The electron energy level emitted by traditional electron guns for charge neutralization of substances is single, the adjustable range of electron energy levels is small, the neutralization range of electrons on the surface of substances is small, and it is easy to excite the original state of substances, which cannot meet the purpose of electron neutralization.

Contents of the invention

In view of the defects in the prior art, the purpose of this utility model is to provide a new type of low-energy electron gun, which has the advantages of low energy, adjustable electron quantity and energy level, compact structure and convenient use.

In order to achieve the above object, the technical solution of the utility model:

A low-energy electron gun, characterized in that it comprises:

Electron-emitting devices that emit electrons;

Acceleration guides the above-mentioned electrons, a grid device for controlling the number and speed of electrons;

focusing means for confining the electron beam formed by said electrons;

an electron gun housing housing the above-mentioned means in its cavity;

And a supporting device for fixing the above-mentioned electron emission device, grid device and focusing device in the cavity of the above-mentioned electron gun shell to play a role of fixed support.

The electron emission device includes a cathode filament at a negative potential, insulating ceramics, a conductive rod at a negative potential, and a filament seat at a negative potential; the cathode filament is fixed on the conductive rod, and releases thermal electrons after being energized and heated; The conductive rod is fixed on the insulating ceramic and passes through the insulating ceramic; the insulating ceramic is located in the grid device and fixed to the grid device through the filament seat.

The grid device is at a negative potential, and its potential is higher than the potential of the cathode filament; the front end of the grid device is insulated from the focusing device by an insulating ball, and its rear end cooperates with the filament holder to fix the insulating ceramic on the grid. The inside of the pole device; at the same time, there is a central hole in the center of the grid device for the thermal electrons released by the cathode filament to pass through.

The focusing device is composed of three ring electrodes that cooperate with each other; one of the ring electrodes is a positive potential electrode, its front end is insulated from the other two ring electrodes by an insulating ball, and its rear end is also insulated from the grid device by an insulating ball Separated; the other two ring electrodes cooperate with each other to form an electrode structure, and the electrode structure is at zero potential.

The electron gun housing includes a gun barrel, a base and a connecting flange; the gun barrel and the base are connected through the connecting flange; and a grid electrode, a cathode electrode and a focusing anode electrode are arranged on the connecting flange.

The support device includes a ceramic rod, a support plate, a spring and an insulating ball; one end of the ceramic rod is fixed on the connecting flange, and the other end is connected to the support plate; the spring is arranged between the filament holder and the support plate, It plays the role of support and buffer; the insulating balls are evenly arranged between the front end of the grid device and the above-mentioned positive potential electrode and between the positive potential electrode and the zero potential electrode structure, and play the role of insulation and isolation.

The material for the electron gun can be selected from SUS304 to meet the requirements of the ultra-high vacuum environment of the electron gun, and it can withstand high temperature baking at a maximum of 250°C.

The setting of each voltage value on the grid electrode, cathode electrode and focusing anode electrode of the electron gun is set by the power controller. By setting different voltage values for the above-mentioned electrodes, the range adjustable emission of thermal electrons, The size of the electron beam spot can be adjusted and other process adjustments.

Main working principle of the utility model:

The corresponding voltage is applied to the electron emission device, grid device and focusing device through the power controller to the grid electrode, cathode electrode and focusing anode electrode, so that the electron gun can work normally; when working, the cathode filament of the emission device is energized and emits electrons at an energy level It has thermal electrons with adjustable high and low level ranges. The potential of the grid device is tens of volts higher than the potential of the cathode filament, and accelerates and guides the electrons passing through the central hole, and controls the number and speed of electrons; through the grid device The electrons enter the focusing device, begin to focus under the action of the electric field force, and finally emit through the frontmost hole. The focusing device can control the size of the beam spot.

The beneficial effects of the utility model:

The electron gun provided by the utility model has the advantages of low energy, adjustable electron quantity and energy level, compact structure and convenient use.

Description of drawings

Fig. 1 is the external view of the low-energy electron gun;

Fig. 2 is the overall internal structure diagram of the low-energy electron gun;

Figure 3 is a cross-sectional view of a low-energy electron gun;

Fig. 4 is a partial sectional view of the front end of the low-energy electron gun;

Fig. 5 is the structural representation of electrode flange;

Figure 6 is a schematic diagram of the control circuit.

In the figure: 1. Ring electrode (1), 2. Ring electrode (3), 3. Insulating ball, 4. Conductive rod, 5. Filament seat, 6. Support plate, 7. Lead wire, 8. Connecting flange, 9 , grid electrode, 10, cathode electrode, 11, base, 12, positioning rod, 13, focusing anode electrode, 14, ceramic rod, 15, spring, 16, insulating ceramic, 17, cathode filament, 18, grid device, 19. Ring electrode (2), 20. Gun barrel, 21. Cathode electrode, 22. Connector, 23. Connector.

Detailed ways

In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model will be further described in detail below in conjunction with the accompanying drawings.

As shown in Fig. 1-Fig. 3, the electron gun described in the utility model mainly includes: an electron emitting device, a grid device, a focusing device, an electron gun shell and a supporting device.

The electron emission device mainly includes: 1) a cathode filament 17 at a negative potential, 2) an insulating ceramic 16, 3) a conductive rod 4 at a negative potential, 4) a filament seat 5 at a negative potential; wherein the cathode filament 17 It is fixed on the conductive rod 4, and releases thermal electrons after being energized and heated; the conductive rod 4 passes through the insulating ceramic 16 and connects with the cathode electrode 10 through the wire 7; Secured with grid assembly.

The grid device is at a negative potential, and its potential is tens of volts higher than that of the cathode filament, so that it can accelerate and guide the thermal electrons released by the cathode filament, thereby controlling the number and speed of emitted electrons; In view of the fact that the grid device is located in front of the filament holder 5 and is directly connected to the filament holder 5, and the filament holder 5 is connected to the cathode electrode 10 through the wire 7 and is at a negative potential, the grid device is also at a negative potential.

The electron gun housing includes a gun barrel 20, a base 11 and a connecting flange 8; the gun barrel 20 and the base 11 are connected by the connecting flange 8; and the connecting flange 8 is provided with a grid electrode 9, a cathode electrode 10 and focusing anode electrode 13.

The focusing device is composed of three ring electrodes (stainless steel): the front end of one ring electrode 2 is insulated from the other two ring electrodes by an insulating ball 3, and its rear end and the front of the grid device are connected to the grid by an insulating ball 3. The pole device is insulated and separated, and it is connected to the focusing anode electrode 13 through a wire, and the focusing anode electrode 13 is adjusted by the voltage of the focusing anode electrode through a variable resistor. The other two rings are directly connected to form an electrode structure, and the ring at the front end is connected to the connecting flange 8 through a wire, and makes the electrode structure at zero potential. Its frontmost ring hole shoots out.

The supporting device is mainly composed of a supporting plate 6 , a spring 15 , an insulating ball 3 and a ceramic rod 14 .

Among them, the insulating ball 3: a number of insulating balls 3 are evenly arranged between the focusing device (positive potential electrode) and the grid device, and holes or V-shaped grooves are correspondingly arranged on the grid device and the focusing device (positive potential electrode) , so that the above-mentioned insulating ball 3 is fixed between the hole and the V-shaped groove. This structural design not only plays the role of separating the focusing device from the grid device, but also keeps the axis of the focusing device parallel to the grid device and produces A uniform and symmetrical electric field is conducive to the passage of electrons and the control of the number of electrons; at the same time, a number of insulating balls are uniformly arranged in the focusing device, and the insulating balls play the role of isolating the positive potential electrode from the other two zero potential electrodes;

The ceramic rod 14 plays a fixing role to the whole device, one end of which is fixed on the connecting flange 8, and the other end is connected with the support plate 6;

The support plate 6 supports the whole device;

The spring 15 is arranged between the filament seat 5 and the support plate 6, and plays a role of supporting and buffering the whole device.

As shown in Fig. 3 - Fig. 5, grid electrode 9, cathode electrode 10, cathode electrode 21, and focusing anode electrode 13 communicate with electron emission device, grid device, focusing device, support device through wire 7 and connector 22, 23 simultaneously corresponding connection.

The grid electrode 9 of the electron gun, the cathode electrode 10 and the setting of each voltage value on the focusing anode electrode 13 are set by the power controller. By setting different voltage values to the above-mentioned electrodes, the range of thermal electrons can be realized Adjustable emission, adjustable electron beam spot size and other process adjustments.

The main working process of the electron gun: during operation, the cathode filament of the electron emission device is energized to emit thermal electrons, and the potential of the grid device is tens of volts higher than that of the cathode filament, which accelerates and guides the above-mentioned thermal electrons; the electrons passing through the grid device After entering the focusing device, it begins to focus under the action of three ring electrodes and finally emits it.

Preferred structure embodiment of the utility model:

As shown in Figures 1 to 6, the electron gun described in the utility model mainly includes: an electron emission device, a grid device, a focusing device, an electron gun shell and a supporting device;

The electron emission device includes a cathode filament 17 , an insulating ceramic 16 , a conductive rod 4 , a wire 7 , and a filament holder 5 . The cathode filament 17 is fixed on the conductive rod 4, and the conductive rod 4 is connected to the cathode electrode 10 and the cathode electrode 21 through the insulating ceramic 16 through the wire 7; It is installed inside the grid device 18 and fixed together with the grid device 18 through the filament holder 5 .

The grid device 18 is a stainless steel structure, which is located in front of the filament holder 5 and is directly connected to the filament holder 5. In view of the fact that the filament holder 5 is connected to the grid electrode 9 through a wire 7 and is at a negative potential, the grid device 18 is also at a negative potential. Negative potential, whose potential is tens of volts higher than the potential of the cathode filament 17 (the specific value is set by the voltage given by the power controller), plays a certain role in accelerating and guiding electrons, so that the number and speed of ejected electrons can be controlled .

Described focusing device is made of ring electrode (one) 1, ring electrode (two) 19 and ring electrode (three) 2; ) 1. Ring electrodes (two) 19 are insulated from each other, and their rear ends are also insulated from the grid device front end 18 by three insulating balls 3, which are connected to the focusing anode electrode 13 by a wire, and the focusing anode electrode 13 The voltage is adjusted by a variable resistor; the ring electrode (1) 1 and the ring electrode (2) 19 are directly connected to form another electrode structure, and the ring electrode (1) 1 at the forefront is connected to the connecting flange 8 through a wire and is at zero Potential; after the hot electrons enter the focusing device, they begin to focus due to the force of the electric field, and finally emit them.

As shown in Fig. 4, the ceramic bar 14 of described supporting device is fixed on the connecting flange 8, and electron emission device, grid device, focusing device, spring 15 and support plate 6 are all fixed on this ceramic bar 14; Between the filament seat 5 and the support plate 6, the support plate 6 is fastened on the ceramic rod 14 by screws; the insulating ball 3 is installed between the grid device and the ring electrode (3) 2 and between the ring electrode (3) 2 and the ring electrode (2) Between 19, as can be seen on Figures 2, 3, and 4, the grid device, the ring-shaped (3) 2 electrodes and the ring-shaped (2) 19 electrodes all have groove designs, so that the insulating ball 3 can be well It is fixed on the top, so that the device maintains a good coaxiality.

Fig. 6 has provided the voltage control circuit schematic diagram of each electrode of electron gun, and each voltage value setting on the grid electrode 9 of described electron gun, cathode electrode 10 and focusing anode electrode 13 is set by power controller, by above-mentioned each The electrodes are set with different voltage values to realize the range-adjustable emission of thermal electrons, the adjustable size of the electron beam spot and other process adjustments.

The above is only a preferred embodiment of the utility model, but the scope of protection of the utility model is not limited thereto. The equivalent replacement or change of the new technical solution and the concept of the utility model shall be covered by the protection scope of the utility model.

Claims (7)

1. a low energy electrons rifle, is characterized in that, comprising:

The electron emitting device of electron emission;

Accelerate to guide above-mentioned electronics, for the gate devices of the quantity and speed that control electronics;

The focusing arrangement that the electron beam formed above-mentioned electronics retrains;

Said apparatus is contained in the electron gun shell in its cavity;

And above-mentioned electron emitting device, gate devices and focusing arrangement are fixed in above-mentioned electron gun shell cavity, the bracing or strutting arrangement play fixed supporting role.

2. low energy electrons rifle according to claim 1, is characterized in that: described electron emitting device comprise be in negative potential cathode filament, insulating ceramics, be in the conducting rod of negative potential and be in the lamp filament of negative potential; Described cathode filament is fixed on described conducting rod, discharges hot electron after heating power; Described conducting rod to be fixed on described insulating ceramics and to pass from described insulating ceramics inside; Described insulating ceramics is positioned at described gate devices, and is fixed by described lamp filament and described gate devices.

3. low energy electrons rifle according to claim 2, it is characterized in that: described gate devices is in negative potential, and its current potential is higher than cathode filament current potential; Insulated separated by insulation ball and focusing arrangement in described gate devices front end, its rear end and lamp filament cooperatively interact and described insulating ceramics is fixed on gate devices inside; Simultaneously described gate devices center has the centre bore that the hot electron that discharges for cathode filament passes through.

4. low energy electrons rifle according to claim 1, is characterized in that: described focusing arrangement is made up of the annular electrode that three cooperatively interact; One of them annular electrode is positive potential electrode, is insulated by insulation ball and all the other two annular electrodes and separate in its front end, is insulated by insulation ball and gate devices equally and separate in its rear end; All the other two annular electrodes cooperatively interact formation one electrode structure, and this electrode structure is in zero potential.

5. low energy electrons rifle according to claim 1, is characterized in that: described electron gun shell comprises gun barrel, base and adpting flange; Described gun barrel is connected by adpting flange with between base; And described adpting flange is arranged gate electrode, cathode electrode and focusing anode electrode.

6. low energy electrons rifle according to claim 4, is characterized in that: described bracing or strutting arrangement comprises ceramic rod, supporting bracket, spring and insulation ball; Described ceramic rod one end is fixedly arranged on adpting flange, and the other end is connected with supporting bracket; Described spring is arranged between lamp filament and supporting bracket, rises and supports and cushioning effect; Described insulation ball is evenly arranged between described gate devices front end and above-mentioned positive potential electrode and between positive potential electrode and zero potential electrode structure respectively, plays insulation buffer action.

7. the low energy electrons rifle according to claim 1-6 any one, is characterized in that: each voltage value on the gate electrode on described electron gun, cathode electrode and focusing anode electrode is set by power-supply controller of electric.