Laser electron gun assembly

Abstract

The utility model relates to a laser electron gun assembly, which is characterized in that a mounting seat is provided with a first through hole, an optical window base is mounted in the first through hole, one end of an optical fiber is connected with a laser generator, the other end of the optical fiber is connected with a focusing collimating lens, the focusing collimating lens is connected with one end of the optical window base, and an optical window is hermetically mounted at the other end of the optical window base. The cathode assembly is installed on the installation base through the focusing electrode, and a laser beam emitted by the laser generator passes through the optical fiber, is focused by the focusing collimating lens and then penetrates through the light window to form a light spot on the cathode assembly. According to the laser electron gun assembly provided by the utility model, the laser beam emitted by the laser generator forms electrons for irradiating the accelerator, the structure is simple, and the manufacturing cost is low. Moreover, according to the laser electron gun assembly provided by the utility model, the defect that a motor is adopted to drive a high-voltage generator to supply power to the filament in the prior art is fundamentally avoided, the overall size is greatly reduced, the diameter is generally smaller than 70mm, and the laser electron gun assembly is convenient to carry and use.

Description

Technical Field

[0001] The utility model relates to a radiation accelerator, and more specifically to a laser electron gun component. Background Art

[0002] It is known that the electron gun assembly is used to form electrons for irradiation accelerators. The electron gun assembly of the prior art uses a motor to drive a generator installed on the head to generate current, and heats the tungsten filament through two electrodes. The kinetic energy of the hot electrons generated by the heated tungsten filament is greater than the work function, so that the electrons leave the surface of the tungsten filament and form an electron cloud near the tungsten filament. The heating of the tungsten filament requires a current of about 20A to be maintained continuously. The adjustment of the accelerator beam size is achieved by adjusting the speed of the generator to change the heating current of the filament. Obviously, the electron gun assembly of the prior art requires continuous power supply to the head, which brings many defects. First, the overall volume of the electron gun assembly is large, whether it is the overall height or the diameter, for example, the diameter reaches 140mm. Secondly, the electron gun assembly has many parts, a complex structure, high manufacturing cost, and great manufacturing difficulty. Thirdly, the electron gun assembly requires a power supply to continuously supply energy to heat the tungsten filament, which consumes a lot of energy. Utility Model Content

[0003] In order to solve the problems of large volume and the like in the above-mentioned prior art, the utility model provides a laser electron gun assembly.

[0004] According to the laser electron gun assembly of the utility model, it includes a laser generator, a mounting seat, a light window base, a focusing collimating lens, an optical fiber, a light window, a focusing electrode and a cathode assembly, wherein the mounting seat is provided with a first through hole, the light window base is mounted in the first through hole, one end of the optical fiber is connected to the laser generator, the other end of the optical fiber is connected to the focusing collimating lens, the focusing collimating lens is connected to one end of the light window base, the light window is sealed and mounted at the other end of the light window base, the cathode assembly is mounted on the mounting seat through the focusing electrode, and the laser beam emitted by the laser generator passes through the optical fiber and is focused by the focusing collimating lens and then passes through the light window to form a light spot on the cathode assembly.

[0005] Preferably, the focusing electrode has a transverse partition, the transverse partition is provided with an annular groove, and the cathode assembly is mounted in the annular groove.

[0006] Preferably, the cathode assembly comprises a cathode and a heat-insulating ceramic ring, the light spot is formed on the cathode, and the heat-insulating ceramic ring is embedded in the annular groove of the transverse partition.

[0007] Preferably, the cathode is a tungsten plate with a rough surface.

[0008] Preferably, the focusing electrode has a flange, and the focusing electrode is connected to the mounting seat via the flange.

[0009] Preferably, the focusing electrode has a flange, the mounting seat has a groove, and the flange is inserted into the groove for installation.

[0010] Preferably, the light window base is provided with a first internal thread, the end of the optical fiber is provided with a coupling joint, the coupling joint is provided with a second internal thread, and the two ends of the focusing collimating lens respectively have a first and a second external thread, the first external thread cooperates with the first internal thread, and the second external thread cooperates with the second internal thread.

[0011] Preferably, the light window base has an annular embedding groove, and the light window is sealed and installed in the annular embedding groove.

[0012] Preferably, the laser generator is a laser generating device that can continuously emit infrared laser or green laser.

[0013] Preferably, the first through hole is a stepped hole.

[0014] According to the laser electron gun assembly of the utility model, the laser beam emitted by the laser generator forms electrons for irradiating the accelerator, and the structure is simple and the manufacturing cost is low. Moreover, according to the laser electron gun assembly of the utility model, the defect of the prior art that the motor drives the high-voltage generator to power the filament is fundamentally avoided, and the overall volume is greatly reduced, usually with a diameter of less than 70 mm, which is easy to carry and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the overall structure of a laser electron gun assembly according to a preferred embodiment of the utility model.

[0016] Figure 2 yes Figure 1 A partial cross-sectional view of .

[0017] Figure 3 yes Figure 1 The first exploded view.

[0018] Figure 4 yes Figure 1 Second exploded view.

[0019] Figure 5 yes Figure 1 Schematic diagram of the structure of the mounting base.

[0020] Figure 6 yes Figure 1 Schematic diagram of the structure of the focusing collimating lens.

[0021] Figure 7 yes Figure 1 Schematic diagram of the structure of the focusing electrode. DETAILED DESCRIPTION

[0022] The preferred embodiments of the present utility model are given below in conjunction with the accompanying drawings and described in detail.

[0023] like Figure 1-Figure 4As shown, a laser electron gun assembly according to a preferred embodiment of the utility model comprises a laser generator (not shown), a mounting seat 1, a light window base 2, a focusing collimating lens 3, an optical fiber 4, a light window 5, a focusing electrode 6 and a cathode assembly 7, wherein the mounting seat 1 is a part of an irradiation accelerator, and the mounting seat 1 is connected to a voltage multiplier assembly with a high voltage of 5 MeV, such as Figure 5 As shown, the center of the mounting base 1 is provided with a first through hole 11. Figure 2 As shown, the first through hole 11 is a stepped hole, the light window base 2 is installed in the first through hole 11 from the top of the mounting base 1, the upper end of the light window base 2 is connected to the lower end of the focusing collimating lens 3, the upper end of the focusing collimating lens 3 is connected to the optical fiber 4, the optical fiber 4 is connected to the laser generator, the light window 5 is sealed and installed at the lower end of the light window base 2, the focusing electrode 6 is installed at the lower end of the mounting base 1, and the cathode assembly 7 is installed on the focusing electrode 6 below the light window 5, so that the laser beam emitted by the laser generator passes through the light window 5 after being focused by the focusing collimating lens 3, and forms a light spot with a diameter of 3.5 mm on the cathode assembly 7, thereby forming an electron cloud for irradiating the accelerator.

[0024] The laser generator is a laser generating device that can generate high-power, high-energy continuous infrared laser or green laser. In this embodiment, the laser generator is a laser generator that can emit infrared laser with a wavelength of 1064nm. In another embodiment, the laser generator is a laser generator that can emit green laser with a wavelength of 532nm.

[0025] The light window base 2 is a tubular structure. The upper end of the light window base 2 is provided with an internal thread. Figure 6 As shown, the lower end of the focusing collimating lens 3 has an outer screw thread 31, which cooperates with the inner screw thread of the upper end of the light window base 2. The lower end of the light window base 2 has an annular groove, and the light window 5 is sealed and installed in the annular groove by, for example, a sealant.

[0026] The end of the optical fiber 4 is provided with a coupling connector 41, and the lower end of the coupling connector 41 is provided with an internal thread. Figure 6 As shown, the upper end of the focusing collimating lens 3 has an external screw thread 32 , and the external screw thread 32 matches with the internal screw thread of the lower end of the coupling joint 41 .

[0027] The light window 5 is made of sapphire with a light transmittance of ≥90%.

[0028] like Figure 7 As shown, the focusing electrode 6 has a flange 61. Figure 5 As shown, the mounting seat 1 has a groove 12, and the flange 61 is inserted into the groove 12 for installation. Figure 2 .like Figure 7 As shown, the focusing electrode 6 has a flange 62, and the focusing electrode 6 is connected to the lower end of the mounting base 1 through the flange 62. Figure 2 As shown, the focusing electrode 6 also has a transverse partition 63, and the transverse partition 63 is provided with an annular groove, and the cathode assembly 7 is installed in the annular groove. It should be understood that the area below the optical window 5 is a vacuum environment.

[0029] The cathode assembly 7 includes a cathode 71 and a heat-insulating ceramic ring 72. A light spot is formed on the cathode 71. The cathode 71 is heated to 2500 degrees Celsius so that the kinetic energy of the electrons is greater than the work function. The electrons leave the surface of the cathode 71 to form an electron cloud. The heat-insulating ceramic ring 72 is embedded in the annular groove of the transverse partition 63. The cathode 71 is fixedly mounted on the transverse partition 63 through the heat-insulating ceramic ring 72. It should be understood that the heating of the cathode 71 by the laser beam is confined to the cathode 71 through the heat-insulating ceramic ring 72. In this embodiment, the cathode 71 is a tungsten plate with a rough surface so that the laser has a larger contact area with the cathode 71 to accelerate the heating speed of the cathode 71. The diameter of the light spot formed by the infrared laser being focused on the cathode 71 through the focusing collimating lens 3 is 3.5 mm. It should be understood that the size of the light spot can be adjusted as needed by setting the distance between the cathode 71 and the focusing collimating lens 3 and the parameters of the focusing collimating lens 3 (such as focal length, diameter and shape, etc.).

[0030] According to a preferred embodiment of the utility model, a method for forming electrons for irradiating an accelerator comprises the following steps: S1, turning on the power of a laser generator to generate an infrared or green laser beam; S2, the laser beam is transmitted to a focusing collimating lens 3 through an optical fiber 4; S3, the focusing collimating lens 3 focuses the laser beam; S4, the focused laser beam passes through an optical window 5 and enters a vacuum chamber inside a focusing electrode 6; S5, a light spot formed by the focused laser beam is irradiated onto the surface of a cathode 71 to heat the cathode 71; S6, the cathode 71 is heated until the kinetic energy of the electrons is greater than the work function, and the electrons leave the surface of the cathode 71 to form an electron cloud; S7, the focusing electrode 6 constrains and gathers the scattered electrons.

[0031] The above is only a preferred embodiment of the utility model, and is not intended to limit the scope of the utility model. The above embodiments of the utility model can also be modified in various ways. That is, all simple, equivalent changes and modifications made according to the claims and the contents of the specification of the utility model application fall within the scope of protection of the claims of the utility model patent. The conventional technical contents are not described in detail in the utility model.

Claims

1. A laser electron gun assembly, characterized in that: The laser electron gun assembly comprises a laser generator, a mounting seat, a light window base, a focusing collimating lens, an optical fiber, a light window, a focusing electrode and a cathode assembly, wherein the mounting seat is provided with a first through hole, the light window base is mounted in the first through hole, one end of the optical fiber is connected to the laser generator, the other end of the optical fiber is connected to the focusing collimating lens, the focusing collimating lens is connected to one end of the light window base, the light window is sealed and mounted at the other end of the light window base, the cathode assembly is mounted on the mounting seat through the focusing electrode, and the laser beam emitted by the laser generator passes through the optical fiber and is focused by the focusing collimating lens and then passes through the light window to form a light spot on the cathode assembly.

2. The laser electron gun assembly according to claim 1, characterized in that: The focusing electrode has a transverse partition plate, the transverse partition plate is provided with an annular groove, and the cathode assembly is installed in the annular groove.

3. The laser electron gun assembly according to claim 2, characterized in that: The cathode assembly comprises a cathode and a heat-insulating ceramic ring, a light spot is formed on the cathode, and the heat-insulating ceramic ring is embedded in an annular groove of a transverse partition.

4. The laser electron gun assembly according to claim 3, characterized in that: The cathode is a tungsten plate with a rough surface.

5. The laser electron gun assembly according to claim 1, characterized in that: The focusing electrode has a flange, and the focusing electrode is connected to the mounting seat through the flange.

6. The laser electron gun assembly according to claim 5, characterized in that: The focusing electrode has a flange, and the mounting seat has a groove, and the flange is inserted into the groove for mounting.

7. The laser electron gun assembly according to claim 1, characterized in that: The light window base is provided with a first internal thread, the end of the optical fiber is provided with a coupling joint, the coupling joint is provided with a second internal thread, and the two ends of the focusing collimating lens are respectively provided with a first and a second external thread, the first external thread cooperates with the first internal thread, and the second external thread cooperates with the second internal thread.

8. The laser electron gun assembly according to claim 1, characterized in that: The light window base is provided with an annular embedding groove, and the light window is sealed and installed in the annular embedding groove.

9. The laser electron gun assembly according to claim 1, characterized in that: The laser generator is a laser generating device that can continuously emit infrared laser or green laser.

10. The laser electron gun assembly according to claim 1, characterized in that: The first through hole is a stepped hole.

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